Fibonacci Number LeetCode Solution

Frequently asked in Amazon Expedia Goldman Sachs Google Microsoft Oracle YahooViews 19

Problem Statement:

Fibonacci Number LeetCode Solution says that – The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is

F(0) = 0, F(1) = 1
F(n) = F(n - 1) + F(n - 2), for n > 1.

Given n, calculate F(n).

Example 1:


 n = 2




 F(2) = F(1) + F(0) = 1 + 0 = 1.

Example 2:


 n = 3




 F(3) = F(2) + F(1) = 1 + 1 = 2.

Example 3:


 n = 4




 F(4) = F(3) + F(2) = 2 + 1 = 3.



  • 0 <= n <= 30


The Fibonacci numbers are the numbers in the following integer sequence:

$1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, ……$. We can see the Fibonacci series sequences in the natural world like the sunflower, the nautilus, and the galaxy.

In mathematical terms, the sequence F(n) of Fibonacci numbers is defined by the recurrence relation


with seed values F(0)=0 and F(1)=1.

The Fibonacci sequence is often used in introductory computer science courses to explain recurrence relations, dynamic programming, and proofs by induction.


  • In order to find Fibonacci Number LeetCode Solution. We will use the concept of Fibonacci. So Fibonacci series generates the subsequent number by adding two previous numbers. The Fibonacci series starts from two numbers − F0 & F1. The initial values of F0 & F1 can be taken 0, 1, or 1, 1
  •                                                                  Fn = Fn-1 + Fn-2

For example,

F5 = 0,1, 1, 2, 3

  Image –

Fibonacci Number LeetCode SolutionPin Fibonacci Number LeetCode SolutionPin

class Solution:
    def fib(self, n: int) -> int:
        if n == 0 or n == 1:
            return n
        a = 0
        b = 1
        for i in range(1,n):
            c = a+b
            a = b
            b = c
        return b
class Solution 
    public int fib(int N)
        if(N <= 1)
            return N;
    int a = 0, b = 1;
    while(N-- > 1)
      int c = a + b;
      a = b;
      b = c;
        return b;

Time Complexity – O(N), As we have traversed only one time.

Space Complexity – O(1), As we haven’t taken any extra space.

Similar Questions –

Top Interview Questions

S.No Interview Question Number of times has been asked
1Delete a node in doubly linked list2887
2Java program to find the number of Nodes in a Binary Tree2541
3Reverse a string without affecting special characters2524
4Palindrome using Recursion2487
5Delete a node of a linked list at given position2022
6Quick Sort1768
7Insert nodes in a linked list in a sorted way (Ascending Order)1708
8Find elements pair from array whose sum equal to number1686
9Sort Elements by Frequency of Occurrences1672
10Write a program to print all permutations of a given string1655
11Find Minimum Distance Between Two Numbers in an Array1517
12Create a Doubly Linked List1483
13Reverse an Array1461
14Smallest window in a string containing all characters of another string1436
15Recursively remove all adjacent duplicates1405
16Find a Triplet That Sum to a Given Value1391
17First Repeating Element1384
18Sum of numbers in String1361
19Arrange Even and Odd number such that Odd comes after Even1357
20Smallest Positive Number Missing in an Unsorted Array1326
21Check if the Elements of an Array are Consecutive1290
22Detect a loop in the Linked List1272
23Largest Sum Contiguous Subarray1260
24Quick Sort on SIngly Linked List1256
25Subarray with Given Sum1247
26Print all Possible Combinations of R Elements in a given Array of size N1245
27Recursive function to do substring search1245
28Find the Maximum Repeating Number in Array1203
29Find the First and Second Smallest Elements1155
30Binary Tree Level order traversal in Java1155
31Maximum Subarray Sum using Divide and Conquer1141
32Check if two linked lists are identical1140
33Remove characters from first string which are in second1114
34Find Leaders in an Array1092
35Swap nodes in the linked list1083
36Find the second most frequent character1034
37Find the Number Occurring Odd Number of Times in an Array1033
38Arrange given Numbers to Form the Biggest Number II1027
39Given a string find its first non-repeating character1014
40Find Triplet in Array With a Given Sum1002
41Given a sorted array and a number x, find the pair in array whose sum is closest to x993
42Total number of occurrences of a given item in the linked list991
43A Program to check if strings are rotations of each other or not987
44Print all possible words from phone digits972
45Find the Missing Number962
46Rearrange Positive and Negative Numbers Alternatively in Array950
47Longest Palindromic Substring944
48Segregate even and odd nodes in a linked list933
49Print Longest common subsequence924
50Transform one string to another using minimum number of given operations911
51Union and Intersection of Two Linked Lists905
52Check rearranged string can form a palindrome895
53Rearrange given Array in Maximum Minimum Form876
54Iterative Implementation of Quick Sort867
55Insertion Sort856
56Count Possible Triangles855
57Multiplication of Two Matrices840
58Count of Triplets With Sum Less than Given Value829
59Stock Buy Sell to Maximize Profit827
60Rotate a Linked List825
61Check if the linked list is palindrome824
62Concatenation of two strings803
63Tug of War797
64Print all duplicates in the input string796
65Count Number of Substrings with K Distinct Character’s793
66Find Nearest Greater and Smaller Element782
67Reverse String Without Temporary Variable776
68The Celebrity Problem771
69Remove ‘b’ and ‘ac’ from a given string769
70Find Pythagorean Triplets from Array768
71Find all Common Elements in Given Three Sorted Arrays763
72Remove all duplicates in an unsorted linked list740
73Find the Row with Maximum Number of 1’s737
74Find the subarray whose sum is equal to a given number X736
75Remove Minimum Characters so that Two Strings Become Anagrams735
76Find the Peak Element from an Array733
77Addition of Two Matrices729
78Find Smallest Missing Number in a Sorted Array725
79Generate all Binary Strings Without Consecutive 1’s723
80A Product Array Puzzle720
81Maximum Sum of Non Consecutive Elements710
82Implement Two Stacks in an Array704
83Lexicographic rank of string697
84Check if Two given Matrices are Identical689
85Maximum Product Subarray II686
86Multiplication of Previous and Next680
87Subtraction of Two Matrices673
88Merge K Sorted Arrays and Print Sorted Output667
89Move All the Zeros to the End of the Given Array664
90Form Minimum Number from Given Sequence of D’s and I’s664
91Divide a string in N equal parts664
92Online Algorithm for Checking Palindrome in a Stream663
93Check whether two strings are anagram of each other656
94Remove recurring digits in a given number655
95Sort a stack using a temporary stack651
96Maximum Circular Subarray Sum648
97Sort a linked list that is sorted alternating ascending and descending644
98Subarray and Subsequence638
99Find the Minimum Element in a Sorted and Rotated Array636
100Move last element of the Linked List at first place632
101First Circular Tour to Visit all the Petrol Bunks632
1023Sum Leetcode Solution627
103Compare two strings(linked lists)627
104Largest Subarray with Equal Number of 0’s and 1’s626
105Maximum Element in an Array which is Increasing and then Decreasing626
106Palindrome Permutations of a String625
107Flattening a linked list623
108Palindromes in a given range620
109Majority Element617
110Minimum insertions to form a shortest palindrome616
111Pangram Checking615
112Run length encoding615
113Print all permutations with repetition612
114Elements Appear more than N/K times in Array611
115Minimum Characters to be Added at Front to Make String Palindrome608
116Most repeating character in a string605
117Two Sum Leetcode Solution601
118Rotate string to get lexicographically minimum string600
119Repeated Subsequence of Length Two or More596
120Merge a linked list into another at alternate positions594
121Rearrange a given linked list in-place594
122Minimum number of Merge Operations to make an Array Palindrome593
123Remove all duplicates in a sorted linked list593
124Print all anagrams together in a sequence of words586
125Reorder an Array According to the Given Indexes580
126Pancake Sorting Problem578
127Merge Overlapping Intervals II566
128Clone a Linked List with next and random pointer565
129Remove duplicates from a string564
130Transpose of a Matrix564
131Longest Palindrome can be Formed by Removing or Rearranging Characters564
132Remove Extra Spaces from a String563
133Smallest Palindrome after Replacement563
134Removing Spaces from a String using stringstream559
135Maximum Sum Increasing Subsequence559
136Size of The Subarray With Maximum Sum557
137Check if a given string is a rotation of a palindrome556
138Partition Problem551
139Generate all Binary Strings from Given Pattern545
140Check whether Strings are K Distance Apart or Not544
141Length of Longest valid Substring541
142Delete Last Occurrence537
143Check if Two given Strings are Isomorphic to each other535
144Find Zeros to be Flipped so that Number of Consecutive 1’s is Maximized533
145Insert Node in the Sorted Linked List531
146Program to Toggle all Characters in a String526
147Maximum difference between two elements such as larger element comes after smaller525
148Given string is interleaving of two other strings or not524
149Count Minimum Steps to Get the given Array514
150Number of Smaller Elements on Right Side512
151Check length of a String is Equal to the Number Appended at its Last511
152Check if all Rows of a Matrix are Circular Rotations of Each Other507
153Find Pair with Given Difference506
154Longest Common Prefix using Divide and Conquer506
155Merge sort better than quick sort for linked lists505
156Compare Two Version Numbers500
157Print all interleavings of given two strings496
158Find nth node of the Linked list from the end496
159Print Reverse of a string (Recursion)495
160Median of Two Sorted Arrays LeetCode Solution494
161Find a Fixed Point in a Given Array494
162Sort 0s 1s and 2s in an Array493
163Reorder Array Using Given Indexes492
164Reverse words in a given string490
165Merge two sorted linked lists such that merged list is in reverse order484
166Find the Subarray of given length with Least Average484
167Split linked list using alternate nodes481
168Print all Palindromic Partitions of a String474
169Print string of odd length in ‘X’ format470
170Find Element Using Binary Search in Sorted Array468
171Find K Length Subarray of Maximum Average465
172Swap Kth Node from beginning with Kth Node from End461
173Find Duplicates in an Array in Most Efficient Way457
174print all palindromic partitions453
175Shortest Superstring Problem453
176Check if String Follows Order of Characters by a Pattern or not450
177Maximum Length of Chain Pairs448
178Sort a String According to Another String446
179Flatten a multilevel linked list445
180Sorting a K Sorted Array438
181Program to add two binary digits431
182Recursively print all the sentences that can be formed from list of word lists427
183Find a Sorted Subsequence of size 3426
184Caesar Cipher425
185Longest Span with same Sum in two Binary Arrays II425
186Longest Common Prefix Using Binary Search II425
187Reverse a Linked List in groups424
188Find the two Numbers with Odd Occurrences in an Unsorted Array422
189Kth Non-repeating Character421
190Reverse a Singly Linked List (Iterative/Non-Recursive)419
191Check if String can Become Empty by Recursively Deleting given Substring414
192Longest Common Prefix Word by Word Matching409
193Rearrange a linked list in Zig-Zag408
194Rotate Image by 90 degrees405
195Permutations of a Given String Using STL403
196Perfect Reversible String403
197Pancake Sorting402
198Find First non-repeating character in a string400
1991`s and 2`s complement of binary number398
200Merging Two Sorted Arrays398
201Increasing Subsequence of Length three with Maximum Product394
202Maximum occurring character in a string393
203List items containing all characters of a given word391
204Find the point where a monotonically increasing function becomes positive first time390
205Sort a linked list with 0s, 1s and 2s389
206Four Elements that Sum to Given389
207Construct a Maximum Sum Linked List out of two Sorted Linked Lists having some Common nodes387
208Longest Common Prefix using Character by Character Matching385
209Count Number of Occurrences in a Sorted Array382
210Palindrome string (number)382
211Valid Parentheses LeetCode Solution380
212Delete N nodes after M379
213Minimum Characters to be Removed to Make a Binary String Alternate376
214Split a string374
215Even Substring Count373
216Recursive Implementation of atoi()371
217Sorting the array of strings369
218Convert a String that is Repetition of a Substring of Length K369
219Check if a Linked list of Strings form a Palindrome365
220Print Shortest Path to Print a String on Screen363
221Maximum Subarray Leetcode Solution361
222Convert string1 to string2 in one edit359
223Print All Distinct Elements of the Array358
224Reverse a String using Stack358
225Nth Character in Concatenated Decimal String357
226Find the first Repeating Number in a Given Array357
227Matrix Chain Multiplication using Dynamic Programming357
228Reverse a singly linked list recursively356
229wildcard character matching355
230Count the number of words355
231Lower Case To Upper Case352
232Can we reverse a linked list in less than O(n) time ?350
233Binary Tree to Doubly linked list347
234Sort Elements by Frequency II344
235Longest Common Subsequence with Permutations343
236Find the Lost Element From a Duplicated Array343
237Merge Two Sorted Arrays340
238Split Four Distinct Strings340
239Find middle of the Linked List335
240Roman to Integer Leetcode Solution334
241Count the Pairs at Same Distance as in English Alphabets334
242Toeplitz Matrix327
243Palindrome Permutation325
244Word Search Leetcode Solution324
245Next Greater Element in an Array324
246N queen problem322
247Move all negative elements to one side of array322
248Searching a node in a Binary Search Tree317
249Find Nth Node315
250Find All Pairs With a Given Difference315
251Sudoku Solver315
252First non Repeating Element314
253String(represents an integer) to value313
254Number of Islands LeetCode Solution313
255Reverse Bits313
256Count Pairs With Given Sum312
257Print all Possible Ways to Break a String in Bracket Form312
258Reverse a String311
259Triplet from three linked lists with given sum311
260Types of Binary Tree310
261Delete a Tree310
262Repeated Substring Pattern309
263Change Gender of a given String309
264How to Efficiently Implement k Stacks in a Single Array?308
265Meeting Rooms II LeetCode Solution307
266Fibonacci numbers306
267Number of sub-strings which recursively add up to 9305
268Delete a node under given conditions305
269Sort an array of strings305
270Most Frequent Element in an Array304
271Longest Palindromic Substring LeetCode Solution304
272Min Stack303
273Reverse a linked list303
274Cuckoo sequence program302
275Dijkstra Algorithm300
276Longest Common Extension298
277Binary Tree297
278Remove spaces from a string296
279House Robber Leetcode Solution296
280Max stack294
281Best Time to Buy and Sell Stock  II Leetcode Solution293
282Subset Leetcode292
283Word Search290
284Shuffle a given Array289
285KMP Algorithm288
286Remove middle points in a linked list of line segments288
287Plus One Leetcode Solution287
288Minimize the maximum difference between the heights286
289Find, second, frequent, character286
290Expression Evaluation286
291Combination Sum Leetcode Solution284
292Search Insert Position Leetcode Solution283
293Reverse words in a string282
294Number Of 1 bits282
295Pair of Positive Negative Values in an Array280
296Evaluation of Postfix Expression280
297Sliding Window Technique279
298Set Matrix Zeroes279
299Min Stack Leetcode Solution276
300Valid Palindrome Leetcode Solution276
301Rabin Karp Algorithm275
302Backspace String Compare273
303Subarray with 0 sum273
304Common elements in all rows of a given matrix273
305Sort linked which is sorted on absolute values272
306Clone a linked list with next and random pointer (Hashing)270
307Merge Sorted Arrays Leetcode Solution270
308Delete middle element of a stack268
309Sqrt(x) Leetcode Solution268
310Reversing a Queue267
311Contains Duplicate II Leetcode Solution265
312Count of index pairs with equal elements in an array264
313Implementation of Deque using Doubly Linked List264
314Tower Of Hanoi263
315Product of array except self263
316Contains Duplicate263
317Reverse individual words262
318String Compression262
319Combination Sum262
320Count subarrays with equal number of 1’s and 0’s262
321Pascal Triangle Leetcode262
322Find Top K (or Most Frequent) Numbers in a Stream261
323Intersection of Two Arrays II Leetcode Solution261
324Minimum swaps required to bring all elements less than or equal to k together260
325How to Delete a Linked List260
326Page Replacement Algorithms in Operating Systems260
327Count Odd Numbers in an Interval Range Leetcode Solution260
328Integer to Roman Leetcode Solution259
329Segregate even and odd numbers258
330Group Words With Same Set of Characters258
331Second Most Repeated Word in a Sequence257
332Sorting array using Stacks256
333Postfix to Infix Conversion256
334Bellman Ford Algorithm256
335Single Number Leetcode Solution256
336Minimum Value to Get Positive Step by Step Sum Leetcode Solution255
337Sort elements by frequency255
338Find sum of non-repeating elements (distinct) elements in an array255
339Sum of minimum and maximum elements of all subarrays of size k255
340Smallest Subarray with k Distinct Numbers254
341Arithmetic Expression Evaluation254
342Add Binary Leetcode Solution253
343K-th Smallest Element in a Sorted Matrix253
344Next Permutation252
345Top K Frequent Words252
346Minimum operation to make all elements equal in array252
347Pow(x, n) Leetcode Solution251
348Construct Binary Tree from Given Inorder and Preorder Traversals251
349Maximum Number of Balloons Leetcode Solution251
350Count subarrays having total distinct elements same as original array250
351Palindrome Linked List Leetcode Solution250
352Given two unsorted arrays find all pairs whose sum is x250
353Convex Hull Algorithm249
354Longest Common Prefix Leetcode Solution249
355Scramble String249
356Special Number248
357Longest Substring Without Repeating Characters LeetCode Solution248
358First element occurring k times in an array248
359Kruskal Algorithm247
360Design a stack that supports getMin() in O(1) time and O(1) extra space247
361Majority Element Leetcode Solution246
362Find duplicates in a given array when elements are not limited to a range245
363Evaluate Division245
364Permutations Leetcode Solution245
365Find Lucky Integer in an Array Leetcode Solution245
366Third Maximum Number Leetcode Solution244
367Reversing the First K elements of a Queue243
368Maximum possible difference of two subsets of an array243
369Spiral Matrix LeetCode Solution243
370Number of Good Pairs Leetcode Solution242
371Running Sum of 1d Array Leetcode Solution242
372Prefix to Infix Conversion242
373Reverse a Number Using Stack242
374Check if two arrays are equal or not242
375Maximum Subarray241
376Fizz Buzz Leetcode241
377Minimum Path Sum241
378Huffman Coding241
379Maximal Square240
380Find the Town Judge Leetcode Solution240
381Find Numbers with Even Number of Digits Leetcode Solution240
382Group Anagrams239
383Swap Nodes in Pairs Leetcode Solutions239
384Count Primes Leetcode Solutions238
385Find the Closest Palindrome number238
386Minimum Absolute Difference Leetcode Solution238
387Minimum Steps to reach target by a Knight238
388Maximum Distance Between two Occurrences of Same Element in Array238
389Single Number238
390Unique Paths238
391Range Sum Query 2D – Immutable Leetcode Solution237
392Sort Array by Increasing Frequency Leetcode Solution237
393Find top three repeated in array237
394Find the first repeating element in an array of integers236
395Cumulative Frequency of Count of Each Element in an Unsorted Array236
396Smallest Element Repeated Exactly K Times236
397Palindrome Substring Queries236
398Pascal’s Triangle II Leetcode Solution235
399Sorting using trivial hash function235
400Convert String To Int235
401Find Number of Employees Under every Employee235
402Zigzag Conversion235
403Leetcode Permutations234
404Implement Stack and Queue using Deque234
405Count Substrings with equal number of 0s, 1s and 2s234
406Find All Numbers Disappeared in an Array Leetcode Solution234
407Remove Minimum Number of Elements Such That no Common Element Exist in both Array234
408Power of Two Leetcode Solution234
409Check if Array Contains Contiguous Integers With Duplicates Allowed233
410Missing Number Leetcode Solution233
411How to Implement Stack Using Priority Queue or Heap?233
412Sort Integers by The Number of 1 Bit Leetcode Solution233
413Print all subarrays with 0 sum233
414Merge Two Sorted Lists Leetcode Solutions233
415Letter Case Permutation233
416Matrix Diagonal Sum Leetcode Solution233
417Expression Contains Redundant Bracket or Not232
418House Robber II Leetcode Solution232
419Length of the largest subarray with contiguous elements232
420Bipartite Graph232
421Print All Distinct Elements of a Given Integer Array231
422Happy Number Leetcode Solution231
423Difference between highest and least frequencies in an array231
424Fizz Buzz231
425Top K Frequent Elements231
426Prim’s Algorithm231
427LRU Cache Implementation231
428Maximum Depth of Binary Tree Leetcode Solution230
429Unique Paths Leetcode Solution230
430Decode String230
431Subset sum problem230
432Sort a stack using recursion230
433Count pairs from two linked lists whose sum is equal to a given value230
434Subarray Sum Equals k230
435Search in Rotated Sorted Array Leetcode Solution229
436Find Median from data Stream229
437Find all pairs (a, b) in an array such that a % b = k229
438Find Winner on a Tic Tac Toe Game Leetcode Solution229
439Average Salary Excluding the Minimum and Maximum Salary Leetcode Solution229
440Subarrays with distinct elements228
441Coin Change 2 Leetcode Solution228
442Reverse Integer228
443Max Consecutive Ones Leetcode Solution228
444Check If N and Its Double Exist Leetcode Solution228
445Nth Catalan Number227
446Reverse a Stack Using Recursion227
447Capacity To Ship Packages Within D Days Leetcode Solution227
448Find elements which are present in first array and not in second226
449Find The Duplicate Number226
450How Many Numbers Are Smaller Than the Current Number Leetcode Solution226
451Monotonic Array LeetCode Solution226
452Find the Difference Leetcode Solution226
453Trapping Rain Water Leetcode Solution225
454Integer to English words225
455Find distinct elements common to all rows of a matrix224
456Floyd Warshall Algorithm224
457Reverse Vowels of a String Leetcode Solution224
458Pair with given product224
459Sum of Subarray Ranges Leetcode Solution224
460Text Justification LeetCode Solution224
461Edit Distance224
462Priority Queue Using Singly Linked List224
463Valid Parenthesis String223
464Subarray Sum Equals K LeetCode Solution223
465Find Index of Closing Bracket for a Given Opening Bracket in an Expression223
466Best Time to Buy and Sell Stock III Leetcode Solution223
467Fibonacci Number LeetCode Solution223
468Subtract the Product and Sum of Digits of an Integer Leetcode Solution223
469Target Sum223
470Reverse a String222
471Kth largest element in an Array Leetcode Solutions222
472Count and Say222
473Remove Duplicates from Sorted Array Leetcode Solution222
474Longest subarray not having more than K distinct elements221
475Find four elements that sum to a given value (Hashmap)220
476Find Minimum In Rotated Sorted Array220
477Generate a String With Characters That Have Odd Counts Leetcode Solution220
478Design Parking System Leetcode Solution220
479Longest Common Prefix using Trie220
480The K Weakest Rows in a Matrix Leetcode Solution220
481Find Common Characters Leetcode Solution220
482Check if a given array contains duplicate elements within k distance from each other220
483Delete a Node from linked list without head pointer220
484MiniMax Algorithm220
485Prefix to Postfix Conversion220
486Jump Game Leetcode Solution220
487Find any one of the multiple repeating elements in read only array219
488Sorting a Queue without Extra Space219
489Intersection of Two Arrays219
490Rearrange a binary string as alternate x and y occurrences219
491Shuffle String Leetcode Solution219
492Find missing elements of a range218
493Flood Fill LeetCode218
494Count number of triplets with product equal to given number218
495Multiply Strings Leetcode Solution218
496Top View of Binary Tree218
497Iterative Tower of Hanoi217
498Shortest Palindrome217
499The Stock Span Problem217
500Word Ladder LeetCode Solution217
501Balanced Binary Tree Leetcode Solution217
502Shuffle the Array Leetcode Solution217
503Degree of an array217
504Substring With Concatenation Of All Words217
505Best Time to Buy and Sell Stock LeetCode Solution217
506Iterative Inorder Traversal of a Binary Tree216
507Find subarray with given sum (Handles Negative Numbers)216
508Priority Queue in C++216
509Next Greater Element I Leetcode Solution216
510Merge Two Sorted Linked Lists216
511Excel Sheet Column Number Leetcode Solution216
512Number of Steps to Reduce a Number to Zero Leetcode Solution216
513K-th Distinct Element in an Array215
514Longest Common Subsequence215
515Kids With the Greatest Number of Candies Leetcode Solution215
516Count and Say Leetcode Solution215
517Check for Balanced Parentheses in an Expression215
518Slowest Key Leetcode Solution215
519Implement Stack using Queues215
520Valid Sudoku215
521Move Zeroes LeetCode Solution215
522Reverse Words in a String III LeetCode Solution215
523Concatenation of Array LeetCode Solution215
524Sum of Left Leaves Leetcode Solutions214
525Peak Index in a Mountain Array214
526Longest Common Prefix using Sorting214
527Max Area of Island214
529Implement a stack using single queue213
530Minimum Knight Moves LeetCode Solution213
531Merge Overlapping Intervals213
532Kth Largest Element in a Stream Leetcode Solution213
533Find First and Last Position of Element in Sorted Array Leetcode Solution213
534Find the Duplicate Element213
535Postfix to Prefix Conversion213
536Largest Perimeter Triangle Leetcode Solution212
537Minimum Moves to Equal Array Elements Leetcode Solution212
538Largest Sum Contiguous Subarray212
539Jewels and Stones Leetcode Solution212
540Convert array into Zig-Zag fashion212
541Minimum Delete Operations to make all Elements of Array Same212
542Is Subsequence Leetcode Solution211
543Arrange given numbers to form the biggest number211
544Find Sum of all unique sub-array sum for a given array211
545Gold Mine Problem211
546Linked List Cycle II LeetCode Solution211
547Smallest Subarray With all Occurrences of a Most Frequent Element211
548Container with Most Water211
549Group Multiple Occurrence of Array Elements Ordered by first Occurrence211
550Delete Node in a Linked List Leetcode Solution210
551Next Greater Frequency Element210
552Excel Sheet Column Title Leetcode Solution210
553Isomorphic Strings Leetcode Solution210
554Hamming Distance210
555Last Stone Weight210
556Zigzag Conversion LeetCode Solution210
557Check if a queue can be sorted into another queue using a stack210
558Find N Unique Integers Sum up to Zero Leetcode Solution210
559Change the Array into Permutation of Numbers From 1 to N210
560How to check if two given sets are disjoint?210
561Contiguous Array Leetcode209
562Convert a normal BST to Balanced BST209
563Minimum Bracket Reversals209
564Koko Eating Bananas Leetcode Solution208
565Count the number of nodes at given level in a tree using BFS208
566Mobile Numeric Keypad Problem208
567Summary Ranges Leetcode Solution208
568N-th Tribonacci Number Leetcode Solution208
569Best Time to Buy and Sell Stock208
570Length of Last Word Leetcode Solution208
571Shuffle an Array208
572Maximum sum rectangle in a 2D matrix208
573Distribute Candies to People Leetcode Solution208
574Minimum Cost to Hire K Workers207
575Implementation of Deque using circular array207
576Valid Anagrams207
577Frog Jump Leetcode Solution206
578Maximum Distance in Array206
579Shortest Path in a Grid with Obstacles Elimination LeetCode Solution206
580Find Words That Can Be Formed by Characters Leetcode Solution206
581Trapping Rain Water LeetCode Solution206
5823Sum Closest LeetCode Solution206
583Maximum path sum in a triangle206
584Decode Ways206
585Number of Provinces Leetcode Solution205
586Remove All Occurrences of a Substring LeetCode Solution205
587Build Array From Permutation Leetcode Solution205
588First negative integer in every window of size k205
589Find if an Expression has Duplicate Parenthesis or Not205
590Rotate Image LeetCode Solution205
591Minimum number of subsets with distinct elements205
592Integer to Roman205
593Relative Sort Array Leetcode Solution205
594LRU Cache LeetCode Solution204
59501 Matrix LeetCode Solution204
596Delete consecutive same words in a sequence204
597Minimum Operations to convert X to Y204
598Combinations Leetcode Solution204
599Minimum number of distinct elements after removing m items203
600Sieve of Eratosthenes203
601Maximum difference between first and last indexes of an element in array203
602Smallest Good Base203
603Island Perimeter Leetcode Solution203
604Word Pattern203
605Iterative Method to find Height of Binary Tree203
606Maximum Number of Occurrences of a Substring Leetcode Solution203
607Longest Increasing Subsequence203
608Sort Characters By Frequency LeetCode Solution202
609Assign Cookies Leetcode Solution202
610Count all subsequences having product less than K202
611XOR Operation in an Array Leetcode Solution202
612Find minimum difference between any two elements201
613Non-overlapping sum of two sets201
614Rotate List Leetcode Solution201
615Minimum insertions to form a palindrome with permutations allowed201
616Remove Linked List Elements Leetcode Solution201
617Insert Interval Leetcode Solution201
618Convert Sorted Array to Binary Search Tree Leetcode Solution201
619GCD Of Two Numbers201
620Find the smallest positive integer value that cannot be represented as sum of any subset of a given array201
621Stone Game LeetCode201
622Reverse a stack without using extra space in O(n)200
623Applications of Breadth First Search and Depth First Search200
624The Knapsack Problem200
625Tracking current Maximum Element in a Stack200
626Same Tree LeetCode Solution200
627Sum of f(a[i], a[j]) over all pairs in an array of n integers200
628Permutation in String Leetcode Solution199
629Unique Binary Search Trees199
630Find the Duplicate Number LeetCode Solution199
631Isomorphic Strings199
632Bubble sort using two Stacks199
633Reorganize String199
634Optimal Account Balancing LeetCode Solution198
635Longest Increasing Path in a Matrix LeetCode Solution198
636Printing brackets in Matrix Chain Multiplication Problem198
637Count Good Nodes in Binary Tree Leetcode Solution198
638Maximum Number of Chocolates to be Distributed Equally Among k Students198
639License Key Formatting Leetcode Solution198
640Find Largest d in Array such that a + b + c = d198
641Defanging an IP Address Leetcode Solution198
642K Empty Slots198
643Distance Between Bus Stops Leetcode Solution198
644Form minimum number from given sequence197
645Employee Free Time LeetCode Solution197
646How to Create Mergable Stack?197
647First Unique Character in a String LeetCode Solution197
648Letter Combinations of a Phone Number197
649Minimum Depth of Binary Tree Leetcode Solution196
650Convert an array to reduced form196
651Replace Elements with Greatest Element on Right Side Leetcode Solution196
652Minimum Number of Steps to Make Two Strings Anagram Leetcode Solutions196
653Painting Fence Algorithm195
654Robot Room Cleaner Leetcode Solution195
655Find Pair with Greatest Product in Array195
656Check If It Is a Straight Line Leetcode Solution195
657Reducing Dishes LeetCode Solution195
658House Robber195
659Sort Array By Parity LeetCode Solution195
660Find pairs with given sum such that elements of pair are in different rows195
661Merge Two Balanced Binary Search Trees195
662Strobogrammatic Number LeetCode Solution195
663Word Wrap Problem195
664Segregate 0s and 1s in an Array194
665K Empty Slots LeetCode194
666Largest subarray with equal number of 0s and 1s194
667Queries for counts of array elements with values in given range194
668Kth Missing Positive Number Leetcode Solution194
669Moving Average from Data Stream Leetcode Solution194
670Convert a Number to Hexadecimal Leetcode Solution194
671Maximum Consecutive Numbers Present in an Array194
672Find Maximum Level sum in Binary Tree193
673String to Integer (atoi) LeetCode Solution193
674Longest Substring with At Least K Repeating Characters LeetCode Solution193
675Partition Labels LeetCode Solution193
676Valid Palindrome II Leetcode Solution193
677Maximum Product of Two Elements in an Array Leetcode Solution193
678Power of Four Leetcode Solution192
679Distance of nearest cell having 1 in a binary matrix192
680Longest Substring with At Most K Distinct Characters LeetCode Solution192
681Partition Array Into Three Parts With Equal Sum Leetcode Solution192
682Dynamic Programming Basics192
683Coin Change Problem192
684Print the Fibonacci numbers in reverse order192
685Reservoir Sampling191
686Longest Span with same Sum in two Binary arrays191
687Find the node with minimum value in a Binary Search Tree191
688Valid Palindrome191
689Find unique character in a string191
690Remove Invalid Parentheses Leetcode Solution191
691String Compression LeetCode Solution191
692Find the Distance Value Between Two Arrays Leetcode Solution191
693Best Time to Buy and Sell Stock with Cooldown Leetcode Solution191
694Check If Two String Arrays are Equivalent Leetcode Solution191
695Sum of All Odd Length Subarrays Leetcode Solution191
696Reverse Only Letters LeetCode Solution190
697Number of Dice Rolls With Target Sum LeetCode Solution190
698Path With Maximum Minimum Value LeetCode Solution190
699Find the largest multiple of 3190
700Wiggle Sort190
701Numbers with prime frequencies greater than or equal to k190
702Unique Paths II Leetcode Solution190
703Find the Smallest Divisor given a Threshold Leetcode Solution190
704Generate all possible sorted arrays from alternate elements of two given sorted arrays190
705Inorder Successor of a node in Binary Tree190
706To Lower Case Leetcode Solution190
707Flipping an Image LeetCode Solution190
708Find Leaves of Binary Tree LeetCode Solution190
709Binary Tree Maximum Path Sum LeetCode Solution190
710Maximum Number of Coins You Can Get Leetcode Solution189
711Edit Distance LeetCode Solution189
712Subset Sum Leetcode189
713Stack Permutations (Check if an array is stack permutation of other)189
714Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest189
715Increasing Decreasing String Leetcode Solution189
716Delete Nth node from the end of the given linked list189
717Factorial Trailing Zeroes Leetcode Solution189
718Non-decreasing Array LeetCode Solution188
719Merge Two Binary Trees LeetCode Solution188
720Race Car LeetCode Solution188
721Sort Array by Increasing Frequency Leetcode Solution188
722Find whether an array is subset of another array188
723Count quadruples from four sorted arrays whose sum is equal to a given value x188
724Bulb Switcher LeetCode Solution188
725Permutation Sequence LeetCode Solution188
726Snakes and Ladders LeetCode Solution188
727Reversing a Queue using Recursion188
728Valid Perfect Square Leetcode Solution187
729Ugly Number Leetcode Solution187
730Binary Tree Zigzag Level Order Traversal LeetCode Solution187
731BFS vs DFS for Binary Tree187
732Perform String Shifts Leetcode187
733Majority Element II Leetcode Solution187
734Lucky Numbers in a Matrix Leetcode Solution187
735Maximum 69 Number Leetcode Solution187
736Populating Next Right Pointers in Each Node187
737Find if Path Exists in Graph Leetcode Solution187
738Find Maximum Depth of Nested Parenthesis in a String187
739String comparison containing wildcards186
740Keyboard Row Leetcode Solution186
741Student Attendance Record I Leetcode Solution186
742Best Meeting Point LeetCode Solution186
743Number of NGEs to the Right186
744Remove brackets from an algebraic string containing + and – operators186
745Tiling Problem186
746Base 7 Leetcode Solution186
747Minimum Cost For Tickets Leetcode Solution186
748Recover Binary Search Tree186
749Merge Sorted Array LeetCode Solution186
750Evaluate Reverse Polish Notation LeetCode Solution186
751Maximum Length of a Concatenated String with Unique Characters Leetcode Solution186
752Restore IP Addresses Leetcode Solution185
753Program for Bridge and Torch problem185
754Find All Possible Recipes from Given Supplies LeetCode Solution185
755Print a Binary Tree in Vertical Order185
756Finding K closest element185
757Morris Traversal185
758Binary Tree zigzag level order Traversal185
759Rank Transform of an Array Leetcode Solution185
760Elements to be added so that all elements of a range are present in array185
761k-th missing element in increasing sequence which is not present in a given sequence185
762Maximum Product of Three Numbers LeetCode Solution185
763Word Pattern LeetCode Solution185
764Valid Number185
765Find Median from Data Stream LeetCode Solution185
766Symmetric Tree Leetcode Solution185
767Split a String in Balanced Strings Leetcode Solution185
768Add and Search Word – Data structure design LeetCode184
769Find All Duplicates in an Array LeetCode Solution184
770Maximum Profit in Job Scheduling Leetcode Solution184
771Partition to K Equal Sum Subsets Leetcode Solution184
772Construct BST from given Preorder Traversal184
773Check if Two Expressions With Brackets are Same184
774N-Queens LeetCode Solution184
775Special Array With X Elements Greater Than or Equal X Leetcode Solution184
776Regular Expression Matching184
777Brick Wall LeetCode Solution184
778Binomial Coefficient184
779Check If Array Pairs Are Divisible by k LeetCode Solution184
780Priority Queue using doubly linked list183
781Sorted Linked List to Balanced BST183
782Minimum Distance Between BST Nodes Leetcode Solution183
783Decompress Run-Length Encoded List Leetcode Solution183
784Hamming Distance Leetcode Solution183
785Growable array based stack183
786Jump Game183
787Search in a Binary Search Tree Leetcode Solution182
788Total Numbers With no Repeated Digits in a Range182
789Kth ancestor of a node in binary tree182
790Merge K Sorted Linked Lists182
791Largest rectangular sub-matrix whose sum is 0182
792Largest Rectangle in Histogram LeetCode Solution182
793Minimize Maximum Pair Sum in Array LeetCode Solution182
794Minimum Height Trees182
795Maximum Depth of N-ary Tree Leetcode Solution182
796Invert Binary Tree LeetCode Solution182
797Sort an array according to the order defined by another array182
798Maximum Difference Between Increasing Elements LeetCode Solution182
799Top K Frequent Words LeetCode Solution182
800Nearest Exit from Entrance in Maze LeetCode Solution182
801Check for Palindrome after every character replacement Query182
802Form Minimum Number From Given Sequence182
803One Edit Distance LeetCode Solution182
804Balanced Expression with Replacement181
805Circular Queue181
806Identify and Mark Unmatched Parenthesis in an Expression181
807Number of Days Between Two Dates LeetCode Solution181
808Minimum sum of multiplications of n numbers181
809Minimum Time Visiting All Points Leetcode Solution181
810Number of Islands II LeetCode Solution181
811Final Prices With a Special Discount in a Shop Leetcode Solution181
812Remove Nth Node From End of List Leetcode Solution181
813Queue based approach for first non-repeating character in a stream180
814Diagonal Traversal of Binary Tree180
815Linked List Cycle180
816Transpose Graph180
817Longest Subarray Having Count of 1s One More than Count of 0s180
818Maximum Nesting Depth of the Parentheses Leetcode Solution180
819Repeated Substring Pattern LeetCode Solution180
820Nested List Weight Sum II LeetCode Solution180
821Relative Ranks Leetcode Solution180
822Search a 2D Matrix II Leetcode Solution179
823Count items common to both the lists but with different prices179
824Deletion in a Binary Tree179
825Minimum time required to rot all oranges179
826Given an Array of Pairs Find all Symmetric Pairs in it179
827Minimum Number of Taps to Open to Water a Garden LeetCode Solution179
828Minimum Swaps to Make Strings Equal Leetcode Solution179
829Crawler Log Folder Leetcode Solution179
830Permutation Coefficient178
831Clone Graph LeetCode Solution178
832Subarray Product Less Than K LeetCode Solution178
833Split Array Into Consecutive Subsequences178
834Number Complement Leetcode Solution178
835Course Schedule II – LeetCode178
836Sort Array By Parity II Leetcode Solution178
837Daily Temperatures Leetcode Solution178
838Binary Search Tree Search and Insertion177
839Find Maximum Sum Possible Equal Sum of Three Stacks177
840Reorder Data in Log Files LeetCode Solution177
841Check if an Array is Stack Sortable177
842A Space Optimized DP solution for 0-1 Knapsack Problem177
843LCS (Longest Common Subsequence) of three strings177
844Minimum Jumps to Reach Home LeetCode Solution177
845Make Two Arrays Equal by Reversing Sub-arrays Leetcode Solution177
846Missing Element in Sorted Array LeetCode Solution177
847Find all permuted rows of a given row in a matrix177
848Subsequence of Size K With the Largest Even Sum LeetCode Solution177
849Distinct adjacent elements in an array177
850Check if stack elements are pairwise consecutive177
851Lemonade Change Leetcode Solution177
852Sliding Window Maximum176
853Design Browser History LeetCode Solution176
854Count Distinct Elements in Every Window of Size K176
855Last Stone Weight II LeetCode Solution176
856Guess Number Higher or Lower LeetCode Solution176
857Minimum number of jumps to reach end176
858Tree Traversal (Preorder, Inorder & Postorder)176
859Subset with sum divisible by m176
860Insert Delete GetRandom176
861Valid Parentheses Leetcode Solution176
862Check if a given array can represent Preorder Traversal of Binary Search Tree176
863Interval Tree175
864Partition List Leetcode Solution175
865Design a Stack With Increment Operation Leetcode Solution175
866Minimum Sum Path in a Triangle175
867An Interesting Method to generate Binary Numbers from 1 to n175
868Path with maximum average value175
869Union and Intersection of two Linked Lists175
870Remove Duplicates from Sorted List II175
871Remove Duplicates from Sorted List LeetCode Solution175
872Alien Dictionary LeetCode Solution175
873Iterative Preorder Traversal175
874Can Place Flowers LeetCode Solution175
875Brightest Position on Street LeetCode Solution174
876Count ways to reach the nth stair using step 1, 2 or 3174
877Infix to Postfix174
878Spiral Matrix II Leetcode Solution174
879Dividing Array into Pairs With Sum Divisible by K174
880Minimum swaps to make sequences increasing174
881Sequences of given length where every element is more than or equal to twice of previous174
882Convert BST to Min Heap174
883Get Maximum in Generated Array Leetcode Solution174
884Minesweeper LeetCode Solution174
885Sum of nearest smaller and greater number173
886Number of Distinct Islands Leetcode Solution173
887Water Bottles Leetcode Solution173
888Rearrange Array such that arr[i] >= arr[j] if i is even and arr[i] <= arr[j] if i is odd and j < i173
889Sort Colors173
890Least Number of Unique Integers after K Removals Leetcode Solution173
891Pattern Occurrences using Stack173
892Find all triplets with zero sum173
893Friends Pairing Problem173
894Find distance between two nodes of a Binary Tree173
895Find the Only Repetitive Element Between 1 to N-1173
896Level order Traversal in Spiral Form173
897Maximum Score After Splitting a String Leetcode Solution173
898Check whether a given Binary Tree is Complete or not173
899Maximum size subarray sum equals k173
900Find the subarray with least average173
901GCDs of given index ranges in an array173
902Diagonal Traverse LeetCode Solution173
903Guess Number Higher or Lower II173
904Sorted Array to Balanced BST173
905Range LCM Queries172
906Matrix Chain Multiplication172
907Range sum queries without updates172
908Check if any two intervals overlap among a given set of intervals172
909Delete And Earn172
910Insert into a Binary Search Tree Leetcode Solution172
911Best Time to Buy and Sell Stock with Transaction Fee Leetcode Solution172
912Shortest Word Distance Leetcode Solution172
913Lexicographical Numbers Leetcode Solution172
914Median of Two Sorted Arrays171
915Diagonal Traversal LeetCode Solution171
916Time Based Key-Value Store LeetCode Solution171
917Robot Bounded In Circle LeetCode Solution171
918Difference Array | Range update query in O(1)171
919Count Negative Numbers in a Sorted Matrix LeetCode Solution171
920A program to check if a binary tree is BST or not171
921All Unique Triplets that Sum up to a Given Value171
922Alien Dictionary171
923Averages of Levels in Binary Tree171
924Iterative Postorder Traversal Using Two Stacks171
925Destination City Leetcode Solution171
926Rearrange an Array Such that arr[i] is equal to i170
927Rearrange Spaces Between Words Leetcode Solution170
928Set Matrix Zeroes Leetcode Solution170
929Construct Complete Binary Tree from its Linked List Representation170
930Binary Tree Longest Consecutive Sequence LeetCode Solution170
931Check if the given array can represent Level Order Traversal of Binary Search Tree170
932Construct the Rectangle Leetcode Solution170
933My Calendar I LeetCode Solution170
934Three way partitioning of an array around a given range170
935Maximum Frequency Stack Leetcode Solution169
936Find Common Characters Leetcode Solution169
937Queue using Stacks169
938Product of Array Except Self LeetCode Solution169
939Count Subarrays with Same Even and Odd Elements169
940Vertical sum in a given binary tree169
941Trim a Binary Search Tree169
942Special Positions in a Binary Matrix Leetcode Solution169
943Count Submatrices With All Ones LeetCode Solution169
944Convert Sorted List to Binary Search Tree169
945Intersection of Two Linked Lists LeetCode Solution169
946Number of Equivalent Domino Pairs Leetcode Solution169
947Merge Two Sorted Lists Leetcode169
948K’th Largest Element in BST when modification to BST is not allowed169
949Spiral Matrix III LeetCode Solution169
950Palindrome Partitioning Leetcode Solution168
951Remove Duplicates from Sorted List II LeetCode Solution168
952Largest area rectangular sub-matrix with equal number of 1’s and 0’s168
953Analyze User Website Visit Pattern LeetCode Solution168
954Word Break168
955Three Consecutive Odds Leetcode Solution168
956Strongly Connected Component168
957Binary array after M range toggle operations168
958Minimum Height Trees LeetCode Solution168
959Longest Palindromic Subsequence167
961Sign of the Product of an Array LeetCode Solution167
962Kth Smallest Element in a BST Leetcode Solution167
963Climbing stairs167
964Create Maximum Number167
9653 Sum167
966BFS for Disconnected Graph167
967Construct BST from its given Level Order Traversal167
968Queries for GCD of all numbers of an array except elements in a given range167
969Combination Sum IV LeetCode Solution166
970Count subarrays where second highest lie before highest166
971Merging Intervals166
972Count pair with Given Sum166
973Longest subsequence such that difference between adjacents is one166
974Maximum Product Subarray166
975Stone Game II Leetcode166
976Unique Paths II166
977Largest Number Leetcode Solution165
978Serialize and Deserialize Binary Tree165
979Count Primes in Ranges165
980Design Hit Counter LeetCode Solution165
981Number of palindromic paths in a matrix165
982Maximize Sum of Array after K Negations Leetcode Solution165
983Breadth First Search (BFS) for a Graph165
984Reverse Nodes in K-Group165
985Find Maximum of Minimum for Every Window Size in a Given Array165
986Depth First Search (DFS) for a Graph165
987Symmetric Tree165
988Longest Nice Substring LeetCode Solution164
989Maximum Length of Repeated Subarray164
990Valid Boomerang Leetcode Solution164
991Binary Search Tree Delete Operation164
992Find number of pairs in an array such that their XOR is 0164
993Maximum Product of Indexes of Next Greater on Left and Right164
994Asteroid Collision LeetCode Solution164
995Find the First Circular Tour that visits all the Petrol Pumps164
996The Maze III LeetCode Solution164
997Can Make Arithmetic Progression From Sequence Leetcode Solution164
998K Closest Points to Origin Leetcode Solution163
999Count pairs from two sorted arrays whose sum is equal to a given value x163
1000Next Permutation Leetcode Solution163
1001String Matching in an Array Leetcode Solution163
1002Palindrome Partitioning163
1003Print Fibonacci sequence using 2 variables163
1004Maximum Subarray Sum Excluding Certain Elements163
1005Kth Smallest Element in a Sorted Matrix LeetCode Solution163
1006Consecutive Characters LeetCode Solution163
1007Graph Valid Tree LeetCode Solution163
1008The Painter’s Partition Problem162
1009Length of Longest Fibonacci Subsequence162
1010Minimum Index Sum of Two Lists162
1011Level Order Traversal of Binary Tree162
1012Maximum Sum of 3 Non-Overlapping Subarrays162
1013Collect maximum points in a grid using two traversals162
1014Find postorder traversal of BST from preorder traversal162
1015Decrypt String from Alphabet to Integer Mapping Leetcode Solution162
1016Find the Difference Leetcode Solution162
1017Shortest Completing Word Leetcode Solution162
1018Shuffle 2n integers as without using extra space162
1019Balanced Binary Tree162
1020Scramble String LeetCode Solution162
1021Height of a generic tree from parent array162
1022Validate Binary Search Tree162
1023Maximum Number of Ways to Partition an Array LeetCode Solution161
1024Largest divisible pairs subset161
1025Maximum length subsequence with difference between adjacent elements as either 0 or 1161
1026Generate Parentheses Leetcode Solution161
1027Merge Sort161
1028Segment Tree161
1029Find Duplicate Subtrees161
1030Print Next Greater Number of Q queries161
1031Available Captures for Rook Leetcode Solution161
1032Invalid Transactions LeetCode Solution161
1033Newman-Conway Sequence161
1034Maximum difference between frequency of two elements such that element having greater frequency is also greater161
1035K maximum sums of overlapping contiguous sub-arrays161
1036Advantages of BST over Hash Table160
1037Number Of Longest Increasing Subsequence160
1038Rearrange an array such that ‘arr[j]’ becomes ‘i’ if ‘arr[i]’ is ‘j’160
1039Binary Search Tree160
1040Insertion in a Binary Tree160
1041Construction of Longest Increasing Subsequence (N log N)160
1042Make The String Great Leetcode Solution160
1043Next Greater Element III LeetCode Solution160
1044Construct Binary Tree from given Parent Array representation160
1045Largest Substring Between Two Equal Characters Leetcode Solution160
1046Custom Sort String Leetcode Solution160
1047First missing positive160
1048Find a Peak Element II LeetCode Solution159
1049Friends Of Appropriate Ages LeetCode Solution159
1050Rearrange array such that even positioned are greater than odd159
1051Count minimum steps to get the given desired array159
1052Boundary Traversal of binary tree159
1053Compute nCr % p159
1054Boolean Parenthesization Problem159
1055Check If a Word Occurs As a Prefix of Any Word in a Sentence Leetcode Solution159
1056Move all negative elements to end in order with extra space allowed159
1057Bitwise AND of Numbers Range LeetCode Solution158
1058Rearrange array such that even index elements are smaller and odd index elements are greater158
1059Path Sum II LeetCode Solution158
1060Iterative Depth First Traversal of Graph158
1061Kill Process LeetCode Solution158
1062Build an Array With Stack Operations Leetcode Solution158
1063Double the first element and move zero to end158
1064Maximum subsequence sum such that no three are consecutive158
1065Subarrays with K Different Integers Leetcode Solution158
1066Remove Duplicates from Sorted Array II Leetcode Solution157
1067Morris Inorder Traversal157
1068Recover Binary Search Tree Leetcode Solution157
1069Remove Palindromic Subsequences Leetcode Solution157
1070Defanging an IP Address LeetCode Solution157
1071Level order traversal using two Queues157
1072Determine Whether Matrix Can Be Obtained By Rotation LeetCode Solution157
1073Find Peak Element157
1074Largest BST Subtree LeetCode Solution157
1075Regular Expression Matching Regular Expression Matching LeetCode Solution156
1076Partition Equal Subset Sum156
1077Maximum weight transformation of a given string156
1078Minimum Size Subarray Sum156
1079Add two numbers156
1080Smallest Common Region Leetcode Solution156
1081Lowest Common Ancestor156
1082Print Right View of a Binary Tree156
1083Employee Importance LeetCode Solution156
1084Palindrome Permutation LeetCode Solution156
1085Binary Tree Right Side View LeetCode Solution155
1086Longest Bitonic Subsequence155
1087Increasing Triplet Subsequence LeetCode Solution155
1088Number of Closed Islands Leetcode Solution155
1089Ugly Number II LeetCode Solution155
1090Remove duplicates from sorted array155
1091Ugly Numbers155
1092Maximize Distance to Closest Person LeetCode Solution155
1093Implement Trie (Prefix Tree) Leetcode Solution155
1094Super Ugly Number155
1095Bus Routes Leetcode Solution154
1096Populating Next Right Pointers in Each Node Leetcode Solution154
1097Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution154
1098Find maximum difference between nearest left and right smaller elements154
1099Valid Tic-Tac-Toe State LeetCode Solution154
1100Palindromic Substrings Leetcode Solution154
1101Path Sum154
1102Sum of Even Numbers After Queries154
1103Binary Tree Data Structure153
1104Search in Sorted Rotated Array153
1105Thousand Separator Leetcode Solution153
1106Find Three Element From Different Three Arrays Such That a + b + c = sum153
1107Find whether a subarray is in form of a mountain or not153
1108Divisible Pairs Counting153
1109Moser-de Bruijn Sequence153
1110Reformat The String Leetcode Solution153
1111Number of siblings of a given Node in n-ary Tree153
1112Print all triplets in sorted array that form AP153
1113Find the minimum distance between two numbers153
1114Number of Students Doing Homework at a Given Time Leetcode Solution152
1115Count Largest Group Leetcode Solution152
1116Find Smallest Range Containing Elements from k Lists152
1117Mean of Array After Removing Some Elements Leetcode Solution152
1118Day of the Year Leetcode Solution152
1119Cells with Odd Values in a Matrix LeetCode Solution152
1120Kth Smallest Product of Two Sorted Arrays LeetCode Solution152
1121Search Insert Position151
1122Products of ranges in an array151
1123Level of Each node in a Tree from source node151
1124Distinct Subsequences151
1125Iterative method to find ancestors of a given binary tree151
1126Root to Leaf path with target sum Leetcode Solutions151
1127Clone a Binary Tree with Random Pointers151
1128Serialize and Deserialize Binary Tree LeetCode Solution151
1129Compare Strings by Frequency of the Smallest Character Leetcode Solution150
1130Third Maximum Number Leetcode Solution150
1131Minimum Absolute Difference in BST Leetcode Solution150
1132Longest Increasing Consecutive Subsequence150
1133Prime Palindrome LeetCode Solution150
1134Topological Sorting150
1135Constant time range add operation on an array150
1136Find Two Non-overlapping Sub-arrays Each With Target Sum LeetCode Solution150
1137Maximum Depth Of Binary Tree149
1138Queries for Number of Distinct Elements in a Subarray149
1139Longest Repeated Subsequence149
1140Find maximum length Snake sequence149
1141Bottom View of a Binary Tree149
1142Maximum Product Subarray149
1143Convert BST into a Min-Heap without using array149
1144Construct K Palindrome Strings LeetCode Solution149
1145Minimum sum of squares of character counts in a given string after removing k characters148
1146Print modified array after executing the commands of addition and subtraction148
1147Rotate Array148
1148Web Crawler LeetCode Solution148
1149Longest Subarray of 1’s After Deleting One Element LeetCode Solution148
1150Diameter of N-Ary Tree LeetCode Solution148
1151Subset Sum Problem in O(sum) space147
1152Write Code to Determine if Two Trees are Identical147
1153Find a sorted subsequence of size 3 in linear time147
1154Search an Element in Sorted Rotated Array147
1155Delete Nodes and Return Forest Leetcode Solution147
1156Count even length binary sequences with same sum of first and second half bits147
1157Maximum Product of Splitted Binary Tree LeetCode Solution147
1158Cutting a Rod147
1159Closest Binary Search Tree Value Leetcode Solution147
1160Minimum Score Triangulation of Polygon Leetcode Solution147
1161Priority Queue147
1162Minimum Cost to Move Chips to The Same Position LeetCode Solution146
1163Find Largest Value in Each Tree Row LeetCode Solution146
1164Search Suggestions System LeetCode Solution146
1165Golomb sequence146
1166Maximize sum of consecutive differences in a circular array146
1167Reformat Date LeetCode Solution146
1168Matchsticks to Square Leetcode Solution146
1169Swap Nodes In Pairs146
1170K’th Largest element in BST using constant extra space145
1171Possible Bipartition LeetCode Solution145
1172Closest Leaf in a Binary Tree LeetCode Solution145
1173Given a binary tree, how do you remove all the half nodes?145
1174Decision Tree145
1175Count Pairs Whose Products Exist in Array145
1176Minimum Sideway Jumps LeetCode Solution145
1177Minimum Swaps To Make Sequences Increasing LeetCode Solution145
1178Transform a BST to Greater sum Tree145
1179Minimum Moves to Equal Array Elements LeetCode Solution145
1180Kth Smallest Number in Multiplication Table Leetcode Solution145
1181Contiguous Array LeetCode Solution145
1182Red-Black Tree Introduction145
1183Path Crossing Leetcode Solution144
1184Remove Max Number of Edges to Keep Graph Fully Traversable Leetcode Solution144
1185Binary Tree to Binary Search Tree Conversion144
1186Maximum Value at a Given Index in a Bounded Array LeetCode Solution144
1187Decrease Elements To Make Array Zigzag LeetCode Solution144
1188Reverse a Path in BST using Queue144
1189Check Array Formation Through Concatenation Leetcode Solution144
1190First Bad Version144
1191Merge two BSTs with limited extra space144
1192Find the smallest binary digit multiple of given number144
1193Maximum Binary Tree143
1194Valid Triangle Number143
1195Maximum number of segments of lengths a, b and c143
1196Replace two consecutive equal values with one greater143
1197Perfect Squares LeetCode Solution143
1198Convert Integer to the Sum of Two No-Zero Integers Leetcode Solution143
1199Sum of Left Leaves LeetCode Solution143
1200Divide Two Integers Leetcode Solution142
1201Sliding Window Median Leetcode Solution142
1202Concatenation of Array LeetCode Solution142
1203Factorial Trailing Zeroes LeetCode Solution142
1204Print n terms of Newman-Conway Sequence142
1205Queue Reconstruction by Height142
1206Number of Orders in the Backlog Leetcode Solution142
1207Maximum sum of pairs with specific difference142
1208Convert Sorted Array to Binary Search Tree LeetCode Solutions142
1209Swapping Nodes in a Linked List Leetcode Solution141
1210Valid Perfect Square LeetCode Solution141
1211Maximum sum bitonic subarray141
1212Champagne Tower LeetCode Solution140
1213Kth Smallest Element in a BST140
1214Lowest Common Ancestor of a Binary Tree Leetcode Solution140
1215New 21 Game140
1216Maximum sum of a path in a Right Number Triangle140
1217Lowest Common Ancestor in Binary Search Tree140
1218How to print maximum number of A’s using given four keys140
1219Longest Common Prefix Using Word by Word Matching139
1220Merge k Sorted Lists Leetcode Solution139
1221Find minimum number of merge operations to make an array palindrome139
1222Flatten 2D Vector LeetCode Solution139
1223Array Queries for multiply replacements and product139
1224Integer Break LeetCode Solution139
1225Queries on Probability of Even or Odd Number in given Ranges139
1226Guess The Word139
1227Filter Restaurants by Vegan-Friendly, Price and Distance Leetcode Solution138
1228Range Sum Query using Sparse Table138
1229Check if all levels of two Binary Tree are anagrams or not138
1230Graph and its representation138
1231Mean of range in array138
1232Moving Stones Until Consecutive Leetcode Solution138
1233Maximum Array from Two given Arrays Keeping Order Same137
1234Missing Number137
1235BST to a Tree with Sum of all Smaller Keys137
1236Contiguous Array137
1237Design Skiplist LeetCode Solution137
1238Range Queries for Longest Correct Bracket Subsequence137
1239Maximize Elements Using Another Array137
1240Print modified array after multiple array range increment operations137
1241Find Minimum in Rotated Sorted Array II LeetCode Solution137
1242LRU Cache Leetcode Solution137
1243Maximum Sum Increasing Subsequence137
1244Count Subsets Having Distinct Even Numbers136
1245Maximum Product Subarray136
1246Bold Words in String LeetCode Solution136
1247Min Cost Climbing Stairs LeetCode Solution136
1248Write a function to get the intersection point of two Linked Lists136
1249Largest Plus Sign Leetcode Solution136
1250Minimum Remove to Make Valid Parentheses LeetCode Solution135
1251The kth Factor of n Leetcode Solution135
1252Check in binary array the number represented by a subarray is odd or even135
1253Arithmetic Slices II – Subsequence LeetCode Solution134
1254Check if each internal node of a BST has exactly one child134
1255Different Ways to Add Parentheses Leetcode Solution134
1256Graph Cloning134
1257Parallel Courses II LeetCode Solution134
1258Find k-th smallest element in BST (Order Statistics in BST)134
1259Power of Two134
1260Minimum Time to Collect All Apples in a Tree LeetCode Solution133
1261Check if two nodes are on the same path in a Tree133
1262Smallest Range II Leetcode Solution132
1263Check for Identical BSTs without building the trees132
1264Image Overlap LeetCode Solution132
1265Print Ancestors of a Given Binary Tree Node Without Recursion132
1266Symmetric Tree LeetCode Solution Leetcode Solution132
1267Check Completeness of a Binary Tree LeetCode Solution132
1268Verify Preorder Serialization of a Binary Tree131
1269Longest Substring Without Repeating Characters Leetcode Solution130
1270Excel Sheet Column Title LeetCode Solution130
1271Orderly Queue LeetCode Solution130
1272Koko Eating Bananas LeetCode Solution130
1273Arranging Coins Leetcode Solution129
1274Merge Sorted Array129
1275Next greater element129
1276Vertical Order Traversal of Binary Tree LeetCode Solution128
1277Number of elements less than or equal to a given number in a given subarray128
1278Largest Submatrix With Rearrangements LeetCode Solution128
1279Count and Toggle Queries on a Binary Array128
1280Array Nesting Leetcode Solution127
1281Palindrome Partitioning126
1282Check If a String Can Break Another String Leetcode Solution126
1283Add Two Numbers II Leetcode Solution125
1284Peeking Iterator LeetCode Solution125
1285Newman–Shanks–Williams prime125
1286Palindrome Number LeetCode Solution125
1287Insert Delete GetRandom O(1) Leetcode Solution125
1288Queries for Decimal Values of Subarrays of a Binary Array125
1289Maximum product of an increasing subsequence125
1290Check if X can give change to every person in the Queue125
1291Range Minimum Query (Square Root Decomposition and Sparse Table)124
1292Find maximum average subarray of k length124
1293Find the Winner of the Circular Game LeetCode Solution124
1294Encoded String With Shortest Length LeetCode Solution122
1295Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution122
1296Continuous Subarray Sum LeetCode Solution121
1297Check given array of size n can represent BST of n levels or not121
1298Binary Tree to Binary Search Tree Conversion using STL set120
1299Jump Game IV LeetCode Solution119
1300Reach a Number LeetCode Solution119
1301Minimum Possible Integer After at Most K Adjacent Swaps On Digits LeetCode Solution119
1302Number of indexes with equal elements in given range119
1303Random Pick Index LeetCode Solution119
1304Minimum Number of People to Teach LeetCode Solution118
1305Minimum Total Space Wasted With K Resizing Operations LeetCode Solution117
1306Convert a BST to a Binary Tree such that sum of all greater keys is added to every key117
1307Convert to Base -2 LeetCode Solution116
1308Design A Leaderboard Leetcode Solution115
1309Queries on XOR of greatest odd divisor of the range115
1310Design Underground System Leetcode Solution114
1311Shifting Letters LeetCode Solution112
1312Print Maximum Length Chain of Pairs111
1313Detect Capital Leetcode Solution111
1314Minimum Swaps to Group All 1’s Together Leetcode Solution110
1315Top K Frequent Elements LeetCode Solution109
1316Count Sub Islands LeetCode Solution108
1317Minimum Path Sum Leetcode Solution107
1318Monotonic Array Leetcode Solution105
1319Odd Even Linked List Leetcode Solution104
1320Substring with Concatenation of All Words Leetcode Solution104
1321Longest Common Subsequence LeetCode Solution102
1322Binary Tree Inorder Traversal LeetCode Solution101
1323Decode String Leetcode Solution101
1324Find the Town Judge LeetCode Solution100
1325Maximum Population Year LeetCode Solution100
1326Shortest Unsorted Continuous Subarray LeetCode Solution95
1327Rectangle Overlap LeetCode Solution94
1328Best Meeting Point LeetCode Solution94
1329Maximum Population Year LeetCode Solution93
1330Find the Town Judge LeetCode Solution92
1331Sum Root to Leaf Numbers LeetCode Solution91
1332Insert into a Sorted Circular Linked List LeetCode Solution91
1333Flatten Binary Tree to Linked List LeetCode Solution89
1334Design Add and Search Words Data Structure LeetCode Solution89
1335Stone Game IV LeetCode Solution88
1336Is Graph Bipartite? LeetCode Solution87
1337Range Sum Query 2D – Immutable LeetCode Solution87
1338Reveal Cards In Increasing Order Leetcode Solution86
1339Valid Triangle Number LeetCode Solution86
1340Score of Parenthesis LeetCode Solution85
1341Divide Chocolate LeetCode Solution81
1342Step-By-Step Directions From a Binary Tree Node to Another LeetCode Solution75
1343Range Sum of BST LeetCode Solution68
1344Reverse Integer Leetcode Solution66
1345Find K Closest Elements LeetCode Solution64
1346Rotate String LeetCode Solution64
1347Sort Colors LeetCode Solution63
1348Maximum Side Length of a Square with Sum Less than or Equal to Threshold LeetCode Solution61
1349Excel Sheet Column Number LeetCode Solution57
1350Maximum Size Subarray Sum Equals k Leetcode Solution50
1351H-Index Leetcode Solution45
1352Camelcase Matching Leetcode Solution45
1353Valid Anagram Leetcode Solution44
1354Most Stones Removed with Same Row or Column LeetCode Solution43
1355Container With Most Water LeetCode Solution42
1356Group Anagrams LeetCode Solution42
1357Sliding Window Maximum LeetCode Solution42
1358Next Permutation LeetCode Solution41
1359High Five LeetCode Solution41
1360Binary Search LeetCode Solution40
1361Find Peak Element LeetCode Solution40
1362Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution38
1363Paint House LeetCode Solution37
1364Minimum Number of Arrows to Burst Balloons LeetCode Solution36
1365Valid Triangle Number LeetCode Solution36
1366Unique Binary Search Trees LeetCode Solution35
1367Next Greater Element I Leetcode Solution35
1368Flatten Binary Tree to Linked List LeetCode Solution35
1369Group Shifted Strings Leetcode Solution34
1370Sentence Screen Fitting LeetCode Solution33
1371Count Good Nodes in Binary Tree LeetCode Solution32
1372The Number of Weak Characters in the Game LeetCode Solution32
1373Isomorphic Strings LeetCode Solution32
1374Swim in Rising Water LeetCode Solution32
1375Closest Binary Search Tree Value II LeetCode Solution31
1376Peak Index in a Mountain Array LeetCode Solution31
1377Insert Delete GetRandom O(1) – Duplicates allowed LeetCode Solution31
1378All Possible Full Binary Trees LeetCode Solution27
1379Split Linked List in Parts Leetcode Solution27
1380Validate Stack Sequences LeetCode Solution26
1381Single Element in a Sorted Array LeetCode Solution26
1382Lowest Common Ancestor of a Binary Search Tree Leetcode Solution25
1383Max Sum of Two Non-Overlapping Subarrays LeetCode Solution25
1384Best Time to Buy and Sell Stock IV LeetCode Solution24
1385Minimum Increment to Make Array Unique Leetcode Solution24
1386Greatest Sum Divisible by Three LeetCode Solution24
1387Find First and Last Position of Element in Sorted Array LeetCode Solution24
1388Implement strStr() LeetCode Solution23
1389Break a Palindrome LeetCode Solution22
1390Implement Rand10() Using Rand7() Leetcode Solution22
1391Stone Game IV LeetCode Solution22
1392Trapping Rain Water II LeetCode Solution22
1393Contains Duplicate LeetCode Solution20
1394Detect Squares LeetCode Solution20
1395Fibonacci Number LeetCode Solution19
1396Remove All Ones With Row and Column Flips Leetcode Solution19
1397Design Bounded Blocking Queue LeetCode Solution18
1398Reverse Nodes in k-Group LeetCode Solution17
1399Invert Binary Tree LeetCode Solution17
1400Minimum Number of Operations to Move All Balls to Each Box LeetCode Solution16
1401Total Hamming Distance LeetCode Solution14
1402Candy LeetCode Solution13
1403Unique Paths III LeetCode Solution11
Translate »