Min Cost Climbing Stairs LeetCode Solution

Problem Statement

Min Cost Climbing Stairs LeetCode Solution – An integer array cost  is given, where cost[i] is the cost of i^th step on a staircase. Once you pay the cost, you can either climb one or two steps.

You can either start from the step with index 0, or the step with index. 1. Return the minimum cost to reach the top of the floor.

Example 1:

Input:

 cost = [10,15,20]

Output:

 15

Explanation:

 You will start at index 1.
- Pay 15 and climb two steps to reach the top.
The total cost is 15.

Example 2:

Input:

 cost = [1,100,1,1,1,100,1,1,100,1]

Output:

 6

Explanation:

 You will start at index 0.
- Pay 1 and climb two steps to reach index 2.
- Pay 1 and climb two steps to reach index 4.
- Pay 1 and climb two steps to reach index 6.
- Pay 1 and climb one step to reach index 7.
- Pay 1 and climb two steps to reach index 9.
- Pay 1 and climb one step to reach the top.
The total cost is 6.

 

Constraints:

• 2 <= cost.length <= 1000
• 0 <= cost[i] <= 999

Approach

1. The Main idea of this problem is to use Dynamic Programming to find minimum cost climbing stairs.

2. We will discuss recursion with memoization as it is beginner-friendly.

3. Now, rec(i) is the minimum cost to the i^th step. we can take one step or two-step from index i.

4. Now, recurrence will be rec(i)=cost[i]+min(rec(i+1),rec(i+2))

5. Base condition will be rec(i)=0 if i>=n where n is the length of the array or our estimated path because we reach the destination so no further movement is possible.

 

Code:

C++ Leetcode Solution:

class Solution {
public:
    #define ll int
    ll dp[1005];
    ll n;
    ll rec(ll i,vector<ll>&a)
    {
        if(i>=n)
            return 0;
        ll &ans=dp[i];
        if(ans!=-1)
            return ans;
        ans=a[i]+min(rec(i+2,a),rec(i+1,a));
       
        return ans;

    }
    int minCostClimbingStairs(vector<int>& cost) {
        memset(dp,-1,sizeof(dp));
         n=cost.size();
        
        return min(rec(1,cost),rec(0,cost));
    }
};

Java Leetcode Solution:

class Solution {
    int rec(int i,int n,int [] a,int[] dp)
    {
        
        if(i>=n)
            return 0;
        
        if(dp[i]!=-1)
            return dp[i];
        dp[i]=a[i]+Math.min(rec(i+2,n,a,dp),rec(i+1,n,a,dp));
       
        return (int)dp[i];
            
    }
    public int minCostClimbingStairs(int[] cost) {
        int n=cost.length;
        int[] dp = new int[n+11];
        Arrays.fill(dp, -1); 
        int a=rec(0,n,cost,dp);
        int b=rec(1,n,cost,dp);
        return (int)(Math.min(a,b));
    }
}

Complexity Analysis of Min Cost Climbing Stairs Leetcode Solution:

Time Complexity

Time complexity will be o(n). Because we are traversing the whole array.

 Space Complexity

Space complexity will be o(n). We are creating dp table of length n to store the value in every index.

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493	Kids With the Greatest Number of Candies Leetcode Solution	180
494	MiniMax Algorithm	180
495	Balanced Binary Tree Leetcode Solution	180
496	Target Sum	180
497	Fizz Buzz	180
498	Jump Game Leetcode Solution	179
499	Reverse a linked list	179
500	Design Parking System Leetcode Solution	179
501	Top View of Binary Tree	179
502	Intersection of Two Arrays	178
503	Convert array into Zig-Zag fashion	178
504	Zigzag Conversion LeetCode Solution	178
505	Pair with given product	178
506	Find subarray with given sum (Handles Negative Numbers)	178
507	Length of Last Word Leetcode Solution	177
508	Priority Queue in C++	177
509	Count and Say Leetcode Solution	177
510	Longest subarray not having more than K distinct elements	177
511	Max Area of Island	177
512	Check if a given array contains duplicate elements within k distance from each other	177
513	Valid Parenthesis String	177
514	Last Stone Weight	177
515	The Stock Span Problem	176
516	Peak Index in a Mountain Array	176
517	Shuffle String Leetcode Solution	176
518	Postfix to Prefix Conversion	176
519	Find N Unique Integers Sum up to Zero Leetcode Solution	176
520	Find four elements that sum to a given value (Hashmap)	176
521	Koko Eating Bananas Leetcode Solution	176
522	Shortest Palindrome	176
523	Prefix to Postfix Conversion	175
524	Find missing elements of a range	175
525	Mobile Numeric Keypad Problem	175
526	Implement a stack using single queue	174
527	Find distinct elements common to all rows of a matrix	174
528	Find any one of the multiple repeating elements in read only array	174
529	K-th Distinct Element in an Array	174
530	Count number of triplets with product equal to given number	174
531	Contiguous Array Leetcode	174
532	Find Index of Closing Bracket for a Given Opening Bracket in an Expression	174
533	Relative Sort Array Leetcode Solution	174
534	Substring With Concatenation Of All Words	174
535	Iterative Inorder Traversal of a Binary Tree	174
536	Longest Common Prefix using Sorting	174
537	N-th Tribonacci Number Leetcode Solution	174
538	Smallest Subarray With all Occurrences of a Most Frequent Element	174
539	Recursion	174
540	Valid Anagrams	173
541	Implement Stack using Queues	173
542	Valid Sudoku	173
543	Largest Perimeter Triangle Leetcode Solution	173
544	Is Subsequence Leetcode Solution	173
545	Excel Sheet Column Title Leetcode Solution	173
546	Implementation of Deque using circular array	173
547	Container with Most Water	173
548	Delete Node in a Linked List Leetcode Solution	173
549	Maximum sum rectangle in a 2D matrix	172
550	01 Matrix LeetCode Solution	172
551	First negative integer in every window of size k	172
552	Best Time to Buy and Sell Stock	172
553	Island Perimeter Leetcode Solution	172
554	Next Greater Frequency Element	172
555	Sum of Left Leaves Leetcode Solutions	172
556	Linked List Cycle II LeetCode Solution	172
557	Build Array From Permutation Leetcode Solution	172
558	Isomorphic Strings Leetcode Solution	172
559	Find Words That Can Be Formed by Characters Leetcode Solution	171
560	Distribute Candies to People Leetcode Solution	171
561	Trapping Rain Water LeetCode Solution	171
562	Convert a normal BST to Balanced BST	171
563	Minimum Operations to convert X to Y	171
564	Minimum Delete Operations to make all Elements of Array Same	171
565	Count the number of nodes at given level in a tree using BFS	170
566	Hamming Distance	170
567	Shuffle an Array	170
568	Remove Linked List Elements Leetcode Solution	170
569	Jewels and Stones Leetcode Solution	170
570	Arrange given numbers to form the biggest number	170
571	Rearrange a binary string as alternate x and y occurrences	170
572	Minimum Bracket Reversals	170
573	Convert Sorted Array to Binary Search Tree Leetcode Solution	169
574	Count all subsequences having product less than K	169
575	The Knapsack Problem	169
576	Integer to Roman	169
577	Gold Mine Problem	169
578	Assign Cookies Leetcode Solution	169
579	Insert Interval Leetcode Solution	169
580	Shortest Path in a Grid with Obstacles Elimination LeetCode Solution	168
581	Maximum path sum in a triangle	168
582	Group Multiple Occurrence of Array Elements Ordered by first Occurrence	168
583	Summary Ranges Leetcode Solution	168
584	Change the Array into Permutation of Numbers From 1 to N	168
585	Check for Balanced Parentheses in an Expression	168
586	Find the smallest positive integer value that cannot be represented as sum of any subset of a given array	168
587	3Sum Closest LeetCode Solution	168
588	Minimum Knight Moves LeetCode Solution	168
589	Minimum number of distinct elements after removing m items	167
590	Decode Ways	167
591	XOR Operation in an Array Leetcode Solution	167
592	Unique Binary Search Trees	167
593	Rotate List Leetcode Solution	167
594	K Empty Slots LeetCode	167
595	Sieve of Eratosthenes	166
596	Same Tree LeetCode Solution	166
597	How to check if two given sets are disjoint?	166
598	LRU Cache LeetCode Solution	166
599	Combinations Leetcode Solution	166
600	Rotate Image LeetCode Solution	166
601	Distance Between Bus Stops Leetcode Solution	166
602	Maximum Distance in Array	166
603	Permutation in String Leetcode Solution	165
604	Find minimum difference between any two elements	165
605	Remove All Occurrences of a Substring LeetCode Solution	165
606	Sort Characters By Frequency LeetCode Solution	165
607	Maximum difference between first and last indexes of an element in array	165
608	Frog Jump Leetcode Solution	165
609	Segregate 0s and 1s in an Array	164
610	Painting Fence Algorithm	164
611	Replace Elements with Greatest Element on Right Side Leetcode Solution	164
612	Best Time to Buy and Sell Stock LeetCode Solution	164
613	Find Sum of all unique sub-array sum for a given array	164
614	Stone Game LeetCode	164
615	Minimum number of subsets with distinct elements	164
616	License Key Formatting Leetcode Solution	164
617	Printing brackets in Matrix Chain Multiplication Problem	164
618	Word Pattern	164
619	Smallest Good Base	163
620	Sort Array By Parity LeetCode Solution	163
621	Minimum insertions to form a palindrome with permutations allowed	163
622	Find if an Expression has Duplicate Parenthesis or Not	163
623	Minimum Depth of Binary Tree Leetcode Solution	163
624	Word Wrap Problem	163
625	Coin Change Problem	162
626	Applications of Breadth First Search and Depth First Search	162
627	Maximum Number of Chocolates to be Distributed Equally Among k Students	162
628	Defanging an IP Address Leetcode Solution	162
629	Find the Duplicate Number LeetCode Solution	162
630	Distance of nearest cell having 1 in a binary matrix	162
631	Minimum Cost to Hire K Workers	161
632	Kth Missing Positive Number Leetcode Solution	161
633	Valid Palindrome II Leetcode Solution	161
634	House Robber	161
635	Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest	161
636	Tracking current Maximum Element in a Stack	161
637	Sum of All Odd Length Subarrays Leetcode Solution	160
638	Binary Tree Zigzag Level Order Traversal LeetCode Solution	160
639	Optimal Account Balancing LeetCode Solution	160
640	Find Maximum Level sum in Binary Tree	160
641	Maximum Consecutive Numbers Present in an Array	160
642	Longest Substring with At Most K Distinct Characters LeetCode Solution	160
643	Longest Increasing Subsequence	160
644	Minimum Number of Steps to Make Two Strings Anagram Leetcode Solutions	160
645	Iterative Method to find Height of Binary Tree	160
646	Power of Four Leetcode Solution	160
647	Non-overlapping sum of two sets	160
648	Isomorphic Strings	160
649	Count Good Nodes in Binary Tree Leetcode Solution	160
650	Merge Two Balanced Binary Search Trees	159
651	K Empty Slots	159
652	Reverse a stack without using extra space in O(n)	159
653	GCD Of Two Numbers	159
654	Delete consecutive same words in a sequence	159
655	Number of Provinces Leetcode Solution	159
656	Check If It Is a Straight Line Leetcode Solution	159
657	Best Time to Buy and Sell Stock with Cooldown Leetcode Solution	159
658	Moving Average from Data Stream Leetcode Solution	159
659	String to Integer (atoi) LeetCode Solution	158
660	Letter Combinations of a Phone Number	158
661	Convert an array to reduced form	158
662	Queries for counts of array elements with values in given range	158
663	Ugly Number Leetcode Solution	158
664	Maximum Number of Coins You Can Get Leetcode Solution	158
665	Check If Two String Arrays are Equivalent Leetcode Solution	158
666	Largest Sum Contiguous Subarray	158
667	Strobogrammatic Number LeetCode Solution	158
668	Wiggle Sort	158
669	Reorganize String	157
670	Number of Dice Rolls With Target Sum LeetCode Solution	157
671	Reducing Dishes LeetCode Solution	157
672	Find the Smallest Divisor given a Threshold Leetcode Solution	157
673	Sum of f(a[i], a[j]) over all pairs in an array of n integers	157
674	Employee Free Time LeetCode Solution	157
675	Subset Sum Leetcode	157
676	Lucky Numbers in a Matrix Leetcode Solution	157
677	How to Create Mergable Stack?	157
678	Form minimum number from given sequence	157
679	Reverse Only Letters LeetCode Solution	157
680	Longest Increasing Path in a Matrix LeetCode Solution	157
681	Check if a queue can be sorted into another queue using a stack	157
682	Increasing Decreasing String Leetcode Solution	157
683	Print the Fibonacci numbers in reverse order	157
684	Longest Substring with At Least K Repeating Characters LeetCode Solution	157
685	Partition Labels LeetCode Solution	157
686	Flipping an Image LeetCode Solution	157
687	Find Largest d in Array such that a + b + c = d	157
688	Inorder Successor of a node in Binary Tree	156
689	Find the Distance Value Between Two Arrays Leetcode Solution	156
690	Reversing a Queue using Recursion	156
691	Valid Perfect Square Leetcode Solution	156
692	Valid Palindrome	156
693	Path With Maximum Minimum Value LeetCode Solution	156
694	Maximum Number of Occurrences of a Substring Leetcode Solution	156
695	Find whether an array is subset of another array	156
696	Unique Paths II Leetcode Solution	156
697	Find Leaves of Binary Tree LeetCode Solution	156
698	Merge Two Binary Trees LeetCode Solution	155
699	BFS vs DFS for Binary Tree	155
700	Robot Room Cleaner Leetcode Solution	155
701	Recover Binary Search Tree	155
702	Permutation Sequence LeetCode Solution	155
703	Partition Array Into Three Parts With Equal Sum Leetcode Solution	155
704	Delete Nth node from the end of the given linked list	155
705	Majority Element II Leetcode Solution	155
706	Reservoir Sampling	155
707	Construct BST from given Preorder Traversal	155
708	Binary Tree zigzag level order Traversal	155
709	To Lower Case Leetcode Solution	155
710	Populating Next Right Pointers in Each Node	155
711	Edit Distance LeetCode Solution	154
712	Find the node with minimum value in a Binary Search Tree	154
713	Hamming Distance Leetcode Solution	154
714	Sort Array by Increasing Frequency Leetcode Solution	154
715	Dynamic Programming Basics	154
716	Add and Search Word – Data structure design LeetCode	154
717	Find pairs with given sum such that elements of pair are in different rows	154
718	Remove Invalid Parentheses Leetcode Solution	154
719	Maximum Product of Three Numbers LeetCode Solution	154
720	Rank Transform of an Array Leetcode Solution	154
721	Maximum Product of Two Elements in an Array Leetcode Solution	154
722	Keyboard Row Leetcode Solution	153
723	Numbers with prime frequencies greater than or equal to k	153
724	Decompress Run-Length Encoded List Leetcode Solution	153
725	Convert a Number to Hexadecimal Leetcode Solution	153
726	Factorial Trailing Zeroes Leetcode Solution	153
727	Restore IP Addresses Leetcode Solution	153
728	String Compression LeetCode Solution	152
729	Deletion in a Binary Tree	152
730	Stack Permutations (Check if an array is stack permutation of other)	152
731	Bulb Switcher LeetCode Solution	152
732	Longest Span with same Sum in two Binary arrays	152
733	Queue based approach for first non-repeating character in a stream	152
734	Search in a Binary Search Tree Leetcode Solution	151
735	Minimum Height Trees	151
736	Linked List Cycle	151
737	Find Maximum Depth of Nested Parenthesis in a String	151
738	Non-decreasing Array LeetCode Solution	151
739	Find All Duplicates in an Array LeetCode Solution	151
740	Symmetric Tree Leetcode Solution	151
741	Minimum Distance Between BST Nodes Leetcode Solution	151
742	Find unique character in a string	151
743	Find the largest multiple of 3	151
744	Largest subarray with equal number of 0s and 1s	151
745	Race Car LeetCode Solution	151
746	Remove Duplicates from Sorted List LeetCode Solution	150
747	Maximum Length of a Concatenated String with Unique Characters Leetcode Solution	150
748	k-th missing element in increasing sequence which is not present in a given sequence	150
749	Find Pair with Greatest Product in Array	150
750	Perform String Shifts Leetcode	150
751	Minimum Cost For Tickets Leetcode Solution	150
752	Best Meeting Point LeetCode Solution	150
753	Bubble sort using two Stacks	150
754	Word Pattern LeetCode Solution	150
755	Invert Binary Tree LeetCode Solution	150
756	First Unique Character in a String LeetCode Solution	150
757	Generate all possible sorted arrays from alternate elements of two given sorted arrays	150
758	Binomial Coefficient	150
759	Check If Array Pairs Are Divisible by k LeetCode Solution	150
760	Find if Path Exists in Graph Leetcode Solution	150
761	Maximum 69 Number Leetcode Solution	150
762	Sorted Linked List to Balanced BST	150
763	Minimize Maximum Pair Sum in Array LeetCode Solution	150
764	Binary Tree Maximum Path Sum LeetCode Solution	150
765	Remove Nth Node From End of List Leetcode Solution	150
766	Diagonal Traversal of Binary Tree	149
767	Search a 2D Matrix II Leetcode Solution	149
768	Morris Traversal	149
769	Kth ancestor of a node in binary tree	149
770	Count quadruples from four sorted arrays whose sum is equal to a given value x	149
771	Find Median from Data Stream LeetCode Solution	149
772	Elements to be added so that all elements of a range are present in array	149
773	Maximum Difference Between Increasing Elements LeetCode Solution	149
774	Growable array based stack	149
775	Student Attendance Record I Leetcode Solution	149
776	Merge K Sorted Linked Lists	149
777	N-Queens LeetCode Solution	149
778	Evaluate Reverse Polish Notation LeetCode Solution	149
779	Finding K closest element	149
780	Jump Game	149
781	Number of Islands II LeetCode Solution	149
782	Largest rectangular sub-matrix whose sum is 0	148
783	Minimum time required to rot all oranges	148
784	Split a String in Balanced Strings Leetcode Solution	148
785	Number Complement Leetcode Solution	148
786	Minimum Time Visiting All Points Leetcode Solution	148
787	Snakes and Ladders LeetCode Solution	148
788	Program for Bridge and Torch problem	148
789	Valid Number	148
790	Maximum Depth of N-ary Tree Leetcode Solution	148
791	Remove brackets from an algebraic string containing + and – operators	148
792	Merge Sorted Array LeetCode Solution	147
793	Sort an array according to the order defined by another array	147
794	Special Array With X Elements Greater Than or Equal X Leetcode Solution	147
795	Transpose Graph	147
796	Get Maximum in Generated Array Leetcode Solution	147
797	Nested List Weight Sum II LeetCode Solution	147
798	Largest Rectangle in Histogram LeetCode Solution	147
799	Relative Ranks Leetcode Solution	147
800	Number of NGEs to the Right	147
801	Minimum number of jumps to reach end	147
802	Nearest Exit from Entrance in Maze LeetCode Solution	147
803	Check for Palindrome after every character replacement Query	147
804	Count items common to both the lists but with different prices	147
805	Remove Duplicates from Sorted List II	147
806	Sort Colors	146
807	Circular Queue	146
808	Friends Pairing Problem	146
809	Longest Subarray Having Count of 1s One More than Count of 0s	146
810	Print a Binary Tree in Vertical Order	146
811	Tiling Problem	146
812	Sort Array By Parity II Leetcode Solution	146
813	Convert BST to Min Heap	146
814	Minimum Number of Taps to Open to Water a Garden LeetCode Solution	146
815	One Edit Distance LeetCode Solution	146
816	Crawler Log Folder Leetcode Solution	146
817	String comparison containing wildcards	146
818	A Space Optimized DP solution for 0-1 Knapsack Problem	146
819	Final Prices With a Special Discount in a Shop Leetcode Solution	146
820	Base 7 Leetcode Solution	146
821	Partition to K Equal Sum Subsets Leetcode Solution	146
822	Reorder Data in Log Files LeetCode Solution	145
823	Alien Dictionary LeetCode Solution	145
824	Minimum swaps to make sequences increasing	145
825	Check if Two Expressions With Brackets are Same	145
826	Clone Graph LeetCode Solution	145
827	Subsequence of Size K With the Largest Even Sum LeetCode Solution	145
828	Subarray Product Less Than K LeetCode Solution	145
829	Regular Expression Matching	145
830	Sorted Array to Balanced BST	145
831	Path with maximum average value	145
832	Interval Tree	145
833	Maximum Profit in Job Scheduling Leetcode Solution	144
834	Iterative Preorder Traversal	144
835	Partition List Leetcode Solution	144
836	Course Schedule II – LeetCode	144
837	Maximum size subarray sum equals k	144
838	Total Numbers With no Repeated Digits in a Range	144
839	Minimum Jumps to Reach Home LeetCode Solution	144
840	Check if a given array can represent Preorder Traversal of Binary Search Tree	144
841	Minimum Swaps to Make Strings Equal Leetcode Solution	144
842	Insert into a Binary Search Tree Leetcode Solution	144
843	Design a Stack With Increment Operation Leetcode Solution	144
844	Guess Number Higher or Lower LeetCode Solution	144
845	Make Two Arrays Equal by Reversing Sub-arrays Leetcode Solution	144
846	Level order Traversal in Spiral Form	144
847	Last Stone Weight II LeetCode Solution	144
848	Priority Queue using doubly linked list	144
849	Find the subarray with least average	144
850	Minimum Sum Path in a Triangle	143
851	Can Place Flowers LeetCode Solution	143
852	Top K Frequent Words LeetCode Solution	143
853	Count Distinct Elements in Every Window of Size K	143
854	Subset with sum divisible by m	143
855	Valid Parentheses Leetcode Solution	143
856	Permutation Coefficient	143
857	Find the Only Repetitive Element Between 1 to N-1	143
858	Brightest Position on Street LeetCode Solution	143
859	Union and Intersection of two Linked Lists	143
860	Find all triplets with zero sum	143
861	Three way partitioning of an array around a given range	142
862	Check if an Array is Stack Sortable	142
863	Water Bottles Leetcode Solution	142
864	Check whether a given Binary Tree is Complete or not	142
865	Find All Possible Recipes from Given Supplies LeetCode Solution	142
866	Brick Wall LeetCode Solution	142
867	Maximum Nesting Depth of the Parentheses Leetcode Solution	142
868	Given an Array of Pairs Find all Symmetric Pairs in it	142
869	Repeated Substring Pattern LeetCode Solution	141
870	Least Number of Unique Integers after K Removals Leetcode Solution	141
871	Lemonade Change Leetcode Solution	141
872	Range sum queries without updates	141
873	Spiral Matrix II Leetcode Solution	141
874	Count ways to reach the nth stair using step 1, 2 or 3	141
875	Tree Traversal (Preorder, Inorder & Postorder)	141
876	Matrix Chain Multiplication	141
877	Rearrange Spaces Between Words Leetcode Solution	141
878	Binary Search Tree Search and Insertion	141
879	LCS (Longest Common Subsequence) of three strings	141
880	Sum of nearest smaller and greater number	141
881	4Sum	141
882	Form Minimum Number From Given Sequence	141
883	Design Browser History LeetCode Solution	141
884	Daily Temperatures Leetcode Solution	141
885	Destination City Leetcode Solution	140
886	Maximum Score After Splitting a String Leetcode Solution	140
887	Find all permuted rows of a given row in a matrix	140
888	An Interesting Method to generate Binary Numbers from 1 to n	140
889	Distinct adjacent elements in an array	140
890	GCDs of given index ranges in an array	140
891	Construct Complete Binary Tree from its Linked List Representation	140
892	Delete And Earn	140
893	Count Negative Numbers in a Sorted Matrix LeetCode Solution	140
894	Shortest Word Distance Leetcode Solution	140
895	Count Subarrays with Same Even and Odd Elements	140
896	Insert Delete GetRandom	140
897	Best Time to Buy and Sell Stock with Transaction Fee Leetcode Solution	140
898	Guess Number Higher or Lower II	140
899	Number of Days Between Two Dates LeetCode Solution	139
900	A program to check if a binary tree is BST or not	139
901	Missing Element in Sorted Array LeetCode Solution	139
902	Find Maximum Sum Possible Equal Sum of Three Stacks	139
903	Check if stack elements are pairwise consecutive	139
904	Robot Bounded In Circle LeetCode Solution	139
905	Balanced Expression with Replacement	139
906	Convert Sorted List to Binary Search Tree	139
907	Check if the given array can represent Level Order Traversal of Binary Search Tree	139
908	Identify and Mark Unmatched Parenthesis in an Expression	139
909	Sequences of given length where every element is more than or equal to twice of previous	139
910	Diagonal Traversal LeetCode Solution	139
911	Set Matrix Zeroes Leetcode Solution	139
912	Queries for GCD of all numbers of an array except elements in a given range	139
913	Rearrange an Array Such that arr[i] is equal to i	139
914	Time Based Key-Value Store LeetCode Solution	139
915	BFS for Disconnected Graph	138
916	Diagonal Traverse LeetCode Solution	138
917	Find Common Characters Leetcode Solution	138
918	Range LCM Queries	138
919	Vertical sum in a given binary tree	138
920	Special Positions in a Binary Matrix Leetcode Solution	138
921	Alien Dictionary	138
922	Find distance between two nodes of a Binary Tree	138
923	Minimum sum of multiplications of n numbers	138
924	Palindrome Partitioning Leetcode Solution	138
925	Number of Distinct Islands Leetcode Solution	137
926	Remove Duplicates from Sorted List II LeetCode Solution	137
927	Merging Intervals	137
928	Longest Palindromic Subsequence	137
929	Stone Game II Leetcode	137
930	Analyze User Website Visit Pattern LeetCode Solution	137
931	Rearrange Array such that arr[i] >= arr[j] if i is even and arr[i] <= arr[j] if i is odd and j < i	137
932	Spiral Matrix III LeetCode Solution	137
933	Merge Two Sorted Lists Leetcode	137
934	Averages of Levels in Binary Tree	136
935	K’th Largest Element in BST when modification to BST is not allowed	136
936	Queue using Stacks	136
937	3 Sum	136
938	Construct the Rectangle Leetcode Solution	136
939	Number of Equivalent Domino Pairs Leetcode Solution	136
940	Can Make Arithmetic Progression From Sequence Leetcode Solution	136
941	Maximum Frequency Stack Leetcode Solution	136
942	Intersection of Two Linked Lists LeetCode Solution	136
943	Lexicographical Numbers Leetcode Solution	136
944	Infix to Postfix	136
945	Sliding Window Maximum	136
946	Print Fibonacci sequence using 2 variables	136
947	Maximum Subarray Sum Excluding Certain Elements	136
948	Maximize Sum of Array after K Negations Leetcode Solution	136
949	Three Consecutive Odds Leetcode Solution	136
950	Breadth First Search (BFS) for a Graph	135
951	Difference Array | Range update query in O(1)	135
952	Minimum Height Trees LeetCode Solution	135
953	Construct BST from its given Level Order Traversal	135
954	Binary array after M range toggle operations	135
955	Count Submatrices With All Ones LeetCode Solution	135
956	Binary Tree Longest Consecutive Sequence LeetCode Solution	135
957	All Unique Triplets that Sum up to a Given Value	135
958	Pattern Occurrences using Stack	135
959	Dividing Array into Pairs With Sum Divisible by K	135
960	Trim a Binary Search Tree	135
961	Median of Two Sorted Arrays	135
962	Largest area rectangular sub-matrix with equal number of 1’s and 0’s	135
963	Check if any two intervals overlap among a given set of intervals	134
964	Largest divisible pairs subset	134
965	Strongly Connected Component	134
966	Word Break	134
967	Reverse Nodes in K-Group	134
968	Check If a Word Occurs As a Prefix of Any Word in a Sentence Leetcode Solution	134
969	Palindrome Partitioning	134
970	Largest Substring Between Two Equal Characters Leetcode Solution	134
971	Height of a generic tree from parent array	134
972	Find Maximum of Minimum for Every Window Size in a Given Array	134
973	Find postorder traversal of BST from preorder traversal	134
974	Newman-Conway Sequence	134
975	Symmetric Tree	133
976	Segment Tree	133
977	Iterative Postorder Traversal Using Two Stacks	133
978	Binary Search Tree Delete Operation	133
979	Depth First Search (DFS) for a Graph	133
980	Kth Smallest Element in a BST Leetcode Solution	133
981	Product of Array Except Self LeetCode Solution	133
982	Shuffle 2n integers as a1-b1-a2-b2-a3-b3-..bn without using extra space	133
983	Split Array Into Consecutive Subsequences	133
984	Create Maximum Number	133
985	First missing positive	133
986	Maximum Product Subarray	133
987	Length of Longest Fibonacci Subsequence	132
988	My Calendar I LeetCode Solution	132
989	Find Duplicate Subtrees	132
990	Level Order Traversal of Binary Tree	132
991	Climbing stairs	132
992	Maximum subsequence sum such that no three are consecutive	132
993	Rearrange array such that even positioned are greater than odd	132
994	Asteroid Collision LeetCode Solution	132
995	The Maze III LeetCode Solution	132
996	Boundary Traversal of binary tree	132
997	Minesweeper LeetCode Solution	132
998	Sign of the Product of an Array LeetCode Solution	132
999	Count pair with Given Sum	132
1000	Count Primes in Ranges	132
1001	Longest subsequence such that difference between adjacents is one	131
1002	Decrypt String from Alphabet to Integer Mapping Leetcode Solution	131
1003	Find the First Circular Tour that visits all the Petrol Pumps	131
1004	Kill Process LeetCode Solution	131
1005	Double the first element and move zero to end	131
1006	Longest Nice Substring LeetCode Solution	131
1007	Partition Equal Subset Sum	131
1008	Unique Paths II	131
1009	K Closest Points to Origin Leetcode Solution	131
1010	Serialize and Deserialize Binary Tree	131
1011	Find the Difference Leetcode Solution	131
1012	Maximum Number of Ways to Partition an Array LeetCode Solution	131
1013	Make The String Great Leetcode Solution	131
1014	Graph Valid Tree LeetCode Solution	130
1015	Insertion in a Binary Tree	130
1016	Maximum Length of Repeated Subarray	130
1017	The Painter’s Partition Problem	130
1018	Largest Number Leetcode Solution	130
1019	Find number of pairs in an array such that their XOR is 0	130
1020	Level order traversal using two Queues	130
1021	Shortest Completing Word Leetcode Solution	130
1022	Valid Boomerang Leetcode Solution	130
1023	Next Greater Element III LeetCode Solution	130
1024	Super Ugly Number	130
1025	Count subarrays where second highest lie before highest	129
1026	Compute nCr % p	129
1027	Number Of Longest Increasing Subsequence	129
1028	Design Hit Counter LeetCode Solution	129
1029	Friends Of Appropriate Ages LeetCode Solution	129
1030	Collect maximum points in a grid using two traversals	129
1031	Ugly Number II LeetCode Solution	129
1032	Advantages of BST over Hash Table	129
1033	Balanced Binary Tree	129
1034	Binary Search Tree	129
1035	Scramble String LeetCode Solution	128
1036	Defanging an IP Address LeetCode Solution	128
1037	Kth Smallest Element in a Sorted Matrix LeetCode Solution	128
1038	Employee Importance LeetCode Solution	128
1039	Implement Trie (Prefix Tree) Leetcode Solution	128
1040	Ugly Numbers	128
1041	Invalid Transactions LeetCode Solution	128
1042	Build an Array With Stack Operations Leetcode Solution	128
1043	String Matching in an Array Leetcode Solution	128
1044	Available Captures for Rook Leetcode Solution	128
1045	Rearrange an array such that ‘arr[j]’ becomes ‘i’ if ‘arr[i]’ is ‘j’	128
1046	Boolean Parenthesization Problem	128
1047	Morris Inorder Traversal	128
1048	Maximum Product of Indexes of Next Greater on Left and Right	128
1049	Move all negative elements to end in order with extra space allowed	128
1050	Construction of Longest Increasing Subsequence (N log N)	128
1051	Number of palindromic paths in a matrix	128
1052	Construct Binary Tree from given Parent Array representation	128
1053	Minimum Size Subarray Sum	128
1054	Regular Expression Matching Regular Expression Matching LeetCode Solution	127
1055	Find Peak Element	127
1056	Maximum length subsequence with difference between adjacent elements as either 0 or 1	127
1057	Find whether a subarray is in form of a mountain or not	127
1058	Maximum Sum of 3 Non-Overlapping Subarrays	127
1059	Minimum Index Sum of Two Lists	127
1060	Count minimum steps to get the given desired array	127
1061	Add two numbers	127
1062	Maximum difference between frequency of two elements such that element having greater frequency is also greater	127
1063	Populating Next Right Pointers in Each Node Leetcode Solution	127
1064	Maximum weight transformation of a given string	127
1065	Longest Bitonic Subsequence	127
1066	Generate Parentheses Leetcode Solution	126
1067	Find the minimum distance between two numbers	126
1068	Validate Binary Search Tree	126
1069	Iterative Depth First Traversal of Graph	126
1070	Lowest Common Ancestor	126
1071	Bitwise AND of Numbers Range LeetCode Solution	126
1072	Remove Duplicates from Sorted Array II Leetcode Solution	126
1073	Recover Binary Search Tree Leetcode Solution	126
1074	Find a Peak Element II LeetCode Solution	126
1075	Combination Sum IV LeetCode Solution	126
1076	Divisible Pairs Counting	126
1077	Custom Sort String Leetcode Solution	126
1078	Day of the Year Leetcode Solution	125
1079	Determine Whether Matrix Can Be Obtained By Rotation LeetCode Solution	125
1080	Number of Closed Islands Leetcode Solution	125
1081	Path Sum II LeetCode Solution	125
1082	Maximize Distance to Closest Person LeetCode Solution	125
1083	Binary Tree Right Side View LeetCode Solution	125
1084	Search in Sorted Rotated Array	125
1085	Binary Tree Data Structure	125
1086	Smallest Common Region Leetcode Solution	125
1087	Largest BST Subtree LeetCode Solution	125
1088	Types of Binary Tree	124
1089	Consecutive Characters LeetCode Solution	124
1090	Path Sum	124
1091	Kth Smallest Product of Two Sorted Arrays LeetCode Solution	124
1092	Print all triplets in sorted array that form AP	124
1093	Subarrays with K Different Integers Leetcode Solution	124
1094	Next Permutation Leetcode Solution	124
1095	Number of Students Doing Homework at a Given Time Leetcode Solution	124
1096	Clone a Binary Tree with Random Pointers	124
1097	Rearrange array such that even index elements are smaller and odd index elements are greater	124
1098	Remove Palindromic Subsequences Leetcode Solution	124
1099	Find Smallest Range Containing Elements from k Lists	124
1100	Level of Each node in a Tree from source node	124
1101	Increasing Triplet Subsequence LeetCode Solution	124
1102	Print Next Greater Number of Q queries	124
1103	Count pairs from two sorted arrays whose sum is equal to a given value x	123
1104	Topological Sorting	123
1105	Distinct Subsequences	123
1106	Serialize and Deserialize Binary Tree LeetCode Solution	123
1107	Number of siblings of a given Node in n-ary Tree	123
1108	Remove duplicates from sorted array	122
1109	Bottom View of a Binary Tree	122
1110	Root to Leaf path with target sum Leetcode Solutions	122
1111	Cutting a Rod	122
1112	Maximum Product Subarray	122
1113	Third Maximum Number Leetcode Solution	122
1114	Constant time range add operation on an array	122
1115	Find maximum difference between nearest left and right smaller elements	122
1116	Valid Tic-Tac-Toe State LeetCode Solution	121
1117	Count Largest Group Leetcode Solution	121
1118	Write Code to Determine if Two Trees are Identical	121
1119	Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution	121
1120	Maximum Binary Tree	121
1121	Print Right View of a Binary Tree	121
1122	Minimum Score Triangulation of Polygon Leetcode Solution	121
1123	Mean of Array After Removing Some Elements Leetcode Solution	121
1124	Find Three Element From Different Three Arrays Such That a + b + c = sum	121
1125	Convert BST into a Min-Heap without using array	121
1126	Search Insert Position	120
1127	Products of ranges in an array	120
1128	Cells with Odd Values in a Matrix LeetCode Solution	120
1129	Minimum sum of squares of character counts in a given string after removing k characters	120
1130	Longest Subarray of 1’s After Deleting One Element LeetCode Solution	120
1131	Search an Element in Sorted Rotated Array	120
1132	Palindrome Permutation LeetCode Solution	120
1133	Golomb sequence	120
1134	Minimum Absolute Difference in BST Leetcode Solution	120
1135	Iterative method to find ancestors of a given binary tree	120
1136	Reformat The String Leetcode Solution	120
1137	Queries for Number of Distinct Elements in a Subarray	120
1138	Find a sorted subsequence of size 3 in linear time	119
1139	Construct K Palindrome Strings LeetCode Solution	119
1140	Sum of Even Numbers After Queries	119
1141	Moser-de Bruijn Sequence	119
1142	Longest Increasing Consecutive Subsequence	119
1143	Red-Black Tree Introduction	119
1144	Closest Binary Search Tree Value Leetcode Solution	119
1145	Thousand Separator Leetcode Solution	119
1146	Print modified array after executing the commands of addition and subtraction	119
1147	Prime Palindrome LeetCode Solution	119
1148	Delete Nodes and Return Forest Leetcode Solution	118
1149	Factorial Trailing Zeroes LeetCode Solution	118
1150	Maximum Product of Splitted Binary Tree LeetCode Solution	118
1151	Find maximum length Snake sequence	118
1152	Bus Routes Leetcode Solution	118
1153	Binary Tree to Binary Search Tree Conversion	118
1154	Merge two BSTs with limited extra space	118
1155	Transform a BST to Greater sum Tree	118
1156	Find the smallest binary digit multiple of given number	117
1157	Number of Orders in the Backlog Leetcode Solution	117
1158	K’th Largest element in BST using constant extra space	117
1159	K maximum sums of overlapping contiguous sub-arrays	117
1160	Count even length binary sequences with same sum of first and second half bits	117
1161	Possible Bipartition LeetCode Solution	117
1162	Check Array Formation Through Concatenation Leetcode Solution	117
1163	Decision Tree	117
1164	Kth Smallest Number in Multiplication Table Leetcode Solution	117
1165	Swap Nodes In Pairs	117
1166	Find Two Non-overlapping Sub-arrays Each With Target Sum LeetCode Solution	117
1167	Longest Repeated Subsequence	117
1168	Palindromic Substrings Leetcode Solution	117
1169	Swapping Nodes in a Linked List Leetcode Solution	116
1170	Subset Sum Problem in O(sum) space	116
1171	Maximize sum of consecutive differences in a circular array	116
1172	Minimum Sideway Jumps LeetCode Solution	116
1173	Rotate Array	116
1174	Compare Strings by Frequency of the Smallest Character Leetcode Solution	116
1175	Minimum Cost to Move Chips to The Same Position LeetCode Solution	116
1176	Priority Queue	116
1177	Web Crawler LeetCode Solution	116
1178	Minimum Moves to Equal Array Elements LeetCode Solution	116
1179	First Bad Version	115
1180	Closest Leaf in a Binary Tree LeetCode Solution	115
1181	Find Largest Value in Each Tree Row LeetCode Solution	115
1182	Search Suggestions System LeetCode Solution	115
1183	Given a binary tree, how do you remove all the half nodes?	114
1184	Remove Max Number of Edges to Keep Graph Fully Traversable Leetcode Solution	114
1185	Decrease Elements To Make Array Zigzag LeetCode Solution	114
1186	Count Pairs Whose Products Exist in Array	114
1187	Queue Reconstruction by Height	114
1188	Diameter of N-Ary Tree LeetCode Solution	114
1189	Matchsticks to Square Leetcode Solution	113
1190	Reverse a Path in BST using Queue	113
1191	Convert Sorted Array to Binary Search Tree LeetCode Solutions	113
1192	Contiguous Array LeetCode Solution	113
1193	Kth Smallest Element in a BST	113
1194	Maximum number of segments of lengths a, b and c	113
1195	Moving Stones Until Consecutive Leetcode Solution	113
1196	Maximum Depth Of Binary Tree	112
1197	Sum of Left Leaves LeetCode Solution	112
1198	Reformat Date LeetCode Solution	112
1199	Lowest Common Ancestor in Binary Search Tree	112
1200	Write a function to get the intersection point of two Linked Lists	112
1201	Valid Triangle Number	112
1202	Filter Restaurants by Vegan-Friendly, Price and Distance Leetcode Solution	112
1203	Champagne Tower LeetCode Solution	112
1204	Array Queries for multiply replacements and product	112
1205	Maximum sum bitonic subarray	112
1206	New 21 Game	111
1207	Range Queries for Longest Correct Bracket Subsequence	111
1208	Maximum sum of pairs with specific difference	111
1209	Integer Break LeetCode Solution	111
1210	Range Sum Query using Sparse Table	111
1211	How to print maximum number of A’s using given four keys	111
1212	Replace two consecutive equal values with one greater	111
1213	Maximum Value at a Given Index in a Bounded Array LeetCode Solution	110
1214	Valid Perfect Square LeetCode Solution	110
1215	Graph and its representation	110
1216	Divide Two Integers Leetcode Solution	110
1217	Guess The Word	110
1218	Concatenation of Array LeetCode Solution	110
1219	Convert Integer to the Sum of Two No-Zero Integers Leetcode Solution	110
1220	Symmetric Tree LeetCode Solution Leetcode Solution	110
1221	Path Crossing Leetcode Solution	110
1222	Design Skiplist LeetCode Solution	110
1223	Merge Sort	109
1224	BST to a Tree with Sum of all Smaller Keys	109
1225	Lowest Common Ancestor of a Binary Tree Leetcode Solution	109
1226	Print modified array after multiple array range increment operations	109
1227	Maximum sum of a path in a Right Number Triangle	109
1228	Check for Identical BSTs without building the trees	109
1229	Perfect Squares LeetCode Solution	109
1230	Arithmetic Slices II – Subsequence LeetCode Solution	109
1231	Check if each internal node of a BST has exactly one child	109
1232	Check Completeness of a Binary Tree LeetCode Solution	109
1233	The kth Factor of n Leetcode Solution	109
1234	Flatten 2D Vector LeetCode Solution	109
1235	Check if all levels of two Binary Tree are anagrams or not	108
1236	Power of Two	108
1237	Minimum Swaps To Make Sequences Increasing LeetCode Solution	108
1238	Count Subsets Having Distinct Even Numbers	108
1239	LRU Cache Leetcode Solution	108
1240	Longest Common Prefix Using Word by Word Matching	108
1241	Queries on Probability of Even or Odd Number in given Ranges	108
1242	Parallel Courses II LeetCode Solution	108
1243	Sliding Window Median Leetcode Solution	108
1244	Image Overlap LeetCode Solution	107
1245	Maximum Array from Two given Arrays Keeping Order Same	107
1246	Mean of range in array	107
1247	Missing Number	107
1248	Find Minimum in Rotated Sorted Array II LeetCode Solution	107
1249	Graph Cloning	107
1250	Largest Plus Sign Leetcode Solution	107
1251	Contiguous Array	107
1252	Maximize Elements Using Another Array	107
1253	Count and Toggle Queries on a Binary Array	107
1254	Bold Words in String LeetCode Solution	106
1255	Maximum Product Subarray	106
1256	Print n terms of Newman-Conway Sequence	106
1257	Find minimum number of merge operations to make an array palindrome	106
1258	Check If a String Can Break Another String Leetcode Solution	106
1259	Minimum Remove to Make Valid Parentheses LeetCode Solution	105
1260	Excel Sheet Column Title LeetCode Solution	105
1261	Verify Preorder Serialization of a Binary Tree	105
1262	Find k-th smallest element in BST (Order Statistics in BST)	105
1263	Merge k Sorted Lists Leetcode Solution	104
1264	Print Ancestors of a Given Binary Tree Node Without Recursion	104
1265	Next greater element	104
1266	Smallest Range II Leetcode Solution	103
1267	Minimum Time to Collect All Apples in a Tree LeetCode Solution	103
1268	Palindrome Partitioning	103
1269	Check if two nodes are on the same path in a Tree	102
1270	Min Cost Climbing Stairs LeetCode Solution	102
1271	Merge Sorted Array	101
1272	Check in binary array the number represented by a subarray is odd or even	101
1273	Orderly Queue LeetCode Solution	101
1274	Koko Eating Bananas LeetCode Solution	100
1275	Peeking Iterator LeetCode Solution	100
1276	Check if X can give change to every person in the Queue	99
1277	Newman–Shanks–Williams prime	99
1278	Number of elements less than or equal to a given number in a given subarray	99
1279	Different Ways to Add Parentheses Leetcode Solution	99
1280	Longest Substring Without Repeating Characters Leetcode Solution	97
1281	Range Minimum Query (Square Root Decomposition and Sparse Table)	97
1282	Largest Submatrix With Rearrangements LeetCode Solution	97
1283	Maximum Sum Increasing Subsequence	97
1284	Find maximum average subarray of k length	97
1285	Queries for Decimal Values of Subarrays of a Binary Array	96
1286	Number of indexes with equal elements in given range	96
1287	Minimum Total Space Wasted With K Resizing Operations LeetCode Solution	95
1288	Maximum product of an increasing subsequence	95
1289	Array Nesting Leetcode Solution	95
1290	Binary Tree to Binary Search Tree Conversion using STL set	94
1291	Check given array of size n can represent BST of n levels or not	94
1292	Arranging Coins Leetcode Solution	93
1293	Minimum Number of People to Teach LeetCode Solution	93
1294	Reach a Number LeetCode Solution	92
1295	Convert to Base -2 LeetCode Solution	92
1296	Queries on XOR of greatest odd divisor of the range	92
1297	Encoded String With Shortest Length LeetCode Solution	92
1298	Jump Game IV LeetCode Solution	92
1299	Random Pick Index LeetCode Solution	92
1300	Find the Winner of the Circular Game LeetCode Solution	92
1301	Convert a BST to a Binary Tree such that sum of all greater keys is added to every key	91
1302	Minimum Possible Integer After at Most K Adjacent Swaps On Digits LeetCode Solution	91
1303	Insert Delete GetRandom O(1) Leetcode Solution	90
1304	Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution	88
1305	Palindrome Number LeetCode Solution	88
1306	Add Two Numbers II Leetcode Solution	87
1307	Vertical Order Traversal of Binary Tree LeetCode Solution	87
1308	Design Underground System Leetcode Solution	86
1309	Continuous Subarray Sum LeetCode Solution	85
1310	Print Maximum Length Chain of Pairs	84
1311	Detect Capital Leetcode Solution	81
1312	Design A Leaderboard Leetcode Solution	79
1313	Top K Frequent Elements LeetCode Solution	79
1314	Substring with Concatenation of All Words Leetcode Solution	78
1315	Minimum Swaps to Group All 1’s Together Leetcode Solution	77
1316	Decode String Leetcode Solution	74
1317	Minimum Path Sum Leetcode Solution	74
1318	Odd Even Linked List Leetcode Solution	72
1319	Binary Tree Inorder Traversal LeetCode Solution	72
1320	Count Sub Islands LeetCode Solution	72
1321	Shortest Unsorted Continuous Subarray LeetCode Solution	71
1322	Shifting Letters LeetCode Solution	71
1323	Best Meeting Point LeetCode Solution	70
1324	Find the Town Judge LeetCode Solution	70
1325	Sum Root to Leaf Numbers LeetCode Solution	70
1326	Maximum Population Year LeetCode Solution	70
1327	Longest Common Subsequence LeetCode Solution	68
1328	Find the Town Judge LeetCode Solution	68
1329	Design Add and Search Words Data Structure LeetCode Solution	67
1330	Score of Parenthesis LeetCode Solution	65
1331	Rectangle Overlap LeetCode Solution	65
1332	Maximum Population Year LeetCode Solution	65
1333	Insert into a Sorted Circular Linked List LeetCode Solution	62
1334	Flatten Binary Tree to Linked List LeetCode Solution	62
1335	Stone Game IV LeetCode Solution	62
1336	Range Sum Query 2D – Immutable LeetCode Solution	60
1337	Is Graph Bipartite? LeetCode Solution	60
1338	Valid Triangle Number LeetCode Solution	59
1339	Reveal Cards In Increasing Order Leetcode Solution	54
1340	Divide Chocolate LeetCode Solution	50
1341	Range Sum of BST LeetCode Solution	43
1342	Step-By-Step Directions From a Binary Tree Node to Another LeetCode Solution	42
1343	Reverse Integer Leetcode Solution	40
1344	Sort Colors LeetCode Solution	37
1345	Find K Closest Elements LeetCode Solution	34
1346	Excel Sheet Column Number LeetCode Solution	33
1347	Rotate String LeetCode Solution	32
1348	Maximum Side Length of a Square with Sum Less than or Equal to Threshold LeetCode Solution	31