Min Cost Climbing Stairs LeetCode Solution

Difficulty Level Easy
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Problem Statement

Min Cost Climbing Stairs LeetCode Solution – An integer array cost  is given, where cost[i] is the cost of ith 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 ith 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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574Count all subsequences having product less than K169
575The Knapsack Problem169
576Integer to Roman169
577Gold Mine Problem169
578Assign Cookies Leetcode Solution169
579Insert Interval Leetcode Solution169
580Shortest Path in a Grid with Obstacles Elimination LeetCode Solution168
581Maximum path sum in a triangle168
582Group Multiple Occurrence of Array Elements Ordered by first Occurrence168
583Summary Ranges Leetcode Solution168
584Change the Array into Permutation of Numbers From 1 to N168
585Check for Balanced Parentheses in an Expression168
586Find the smallest positive integer value that cannot be represented as sum of any subset of a given array168
5873Sum Closest LeetCode Solution168
588Minimum Knight Moves LeetCode Solution168
589Minimum number of distinct elements after removing m items167
590Decode Ways167
591XOR Operation in an Array Leetcode Solution167
592Unique Binary Search Trees167
593Rotate List Leetcode Solution167
594K Empty Slots LeetCode167
595Sieve of Eratosthenes166
596Same Tree LeetCode Solution166
597How to check if two given sets are disjoint?166
598LRU Cache LeetCode Solution166
599Combinations Leetcode Solution166
600Rotate Image LeetCode Solution166
601Distance Between Bus Stops Leetcode Solution166
602Maximum Distance in Array166
603Permutation in String Leetcode Solution165
604Find minimum difference between any two elements165
605Remove All Occurrences of a Substring LeetCode Solution165
606Sort Characters By Frequency LeetCode Solution165
607Maximum difference between first and last indexes of an element in array165
608Frog Jump Leetcode Solution165
609Segregate 0s and 1s in an Array164
610Painting Fence Algorithm164
611Replace Elements with Greatest Element on Right Side Leetcode Solution164
612Best Time to Buy and Sell Stock LeetCode Solution164
613Find Sum of all unique sub-array sum for a given array164
614Stone Game LeetCode164
615Minimum number of subsets with distinct elements164
616License Key Formatting Leetcode Solution164
617Printing brackets in Matrix Chain Multiplication Problem164
618Word Pattern164
619Smallest Good Base163
620Sort Array By Parity LeetCode Solution163
621Minimum insertions to form a palindrome with permutations allowed163
622Find if an Expression has Duplicate Parenthesis or Not163
623Minimum Depth of Binary Tree Leetcode Solution163
624Word Wrap Problem163
625Coin Change Problem162
626Applications of Breadth First Search and Depth First Search162
627Maximum Number of Chocolates to be Distributed Equally Among k Students162
628Defanging an IP Address Leetcode Solution162
629Find the Duplicate Number LeetCode Solution162
630Distance of nearest cell having 1 in a binary matrix162
631Minimum Cost to Hire K Workers161
632Kth Missing Positive Number Leetcode Solution161
633Valid Palindrome II Leetcode Solution161
634House Robber161
635Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest161
636Tracking current Maximum Element in a Stack161
637Sum of All Odd Length Subarrays Leetcode Solution160
638Binary Tree Zigzag Level Order Traversal LeetCode Solution160
639Optimal Account Balancing LeetCode Solution160
640Find Maximum Level sum in Binary Tree160
641Maximum Consecutive Numbers Present in an Array160
642Longest Substring with At Most K Distinct Characters LeetCode Solution160
643Longest Increasing Subsequence160
644Minimum Number of Steps to Make Two Strings Anagram Leetcode Solutions160
645Iterative Method to find Height of Binary Tree160
646Power of Four Leetcode Solution160
647Non-overlapping sum of two sets160
648Isomorphic Strings160
649Count Good Nodes in Binary Tree Leetcode Solution160
650Merge Two Balanced Binary Search Trees159
651K Empty Slots159
652Reverse a stack without using extra space in O(n)159
653GCD Of Two Numbers159
654Delete consecutive same words in a sequence159
655Number of Provinces Leetcode Solution159
656Check If It Is a Straight Line Leetcode Solution159
657Best Time to Buy and Sell Stock with Cooldown Leetcode Solution159
658Moving Average from Data Stream Leetcode Solution159
659String to Integer (atoi) LeetCode Solution158
660Letter Combinations of a Phone Number158
661Convert an array to reduced form158
662Queries for counts of array elements with values in given range158
663Ugly Number Leetcode Solution158
664Maximum Number of Coins You Can Get Leetcode Solution158
665Check If Two String Arrays are Equivalent Leetcode Solution158
666Largest Sum Contiguous Subarray158
667Strobogrammatic Number LeetCode Solution158
668Wiggle Sort158
669Reorganize String157
670Number of Dice Rolls With Target Sum LeetCode Solution157
671Reducing Dishes LeetCode Solution157
672Find the Smallest Divisor given a Threshold Leetcode Solution157
673Sum of f(a[i], a[j]) over all pairs in an array of n integers157
674Employee Free Time LeetCode Solution157
675Subset Sum Leetcode157
676Lucky Numbers in a Matrix Leetcode Solution157
677How to Create Mergable Stack?157
678Form minimum number from given sequence157
679Reverse Only Letters LeetCode Solution157
680Longest Increasing Path in a Matrix LeetCode Solution157
681Check if a queue can be sorted into another queue using a stack157
682Increasing Decreasing String Leetcode Solution157
683Print the Fibonacci numbers in reverse order157
684Longest Substring with At Least K Repeating Characters LeetCode Solution157
685Partition Labels LeetCode Solution157
686Flipping an Image LeetCode Solution157
687Find Largest d in Array such that a + b + c = d157
688Inorder Successor of a node in Binary Tree156
689Find the Distance Value Between Two Arrays Leetcode Solution156
690Reversing a Queue using Recursion156
691Valid Perfect Square Leetcode Solution156
692Valid Palindrome156
693Path With Maximum Minimum Value LeetCode Solution156
694Maximum Number of Occurrences of a Substring Leetcode Solution156
695Find whether an array is subset of another array156
696Unique Paths II Leetcode Solution156
697Find Leaves of Binary Tree LeetCode Solution156
698Merge Two Binary Trees LeetCode Solution155
699BFS vs DFS for Binary Tree155
700Robot Room Cleaner Leetcode Solution155
701Recover Binary Search Tree155
702Permutation Sequence LeetCode Solution155
703Partition Array Into Three Parts With Equal Sum Leetcode Solution155
704Delete Nth node from the end of the given linked list155
705Majority Element II Leetcode Solution155
706Reservoir Sampling155
707Construct BST from given Preorder Traversal155
708Binary Tree zigzag level order Traversal155
709To Lower Case Leetcode Solution155
710Populating Next Right Pointers in Each Node155
711Edit Distance LeetCode Solution154
712Find the node with minimum value in a Binary Search Tree154
713Hamming Distance Leetcode Solution154
714Sort Array by Increasing Frequency Leetcode Solution154
715Dynamic Programming Basics154
716Add and Search Word – Data structure design LeetCode154
717Find pairs with given sum such that elements of pair are in different rows154
718Remove Invalid Parentheses Leetcode Solution154
719Maximum Product of Three Numbers LeetCode Solution154
720Rank Transform of an Array Leetcode Solution154
721Maximum Product of Two Elements in an Array Leetcode Solution154
722Keyboard Row Leetcode Solution153
723Numbers with prime frequencies greater than or equal to k153
724Decompress Run-Length Encoded List Leetcode Solution153
725Convert a Number to Hexadecimal Leetcode Solution153
726Factorial Trailing Zeroes Leetcode Solution153
727Restore IP Addresses Leetcode Solution153
728String Compression LeetCode Solution152
729Deletion in a Binary Tree152
730Stack Permutations (Check if an array is stack permutation of other)152
731Bulb Switcher LeetCode Solution152
732Longest Span with same Sum in two Binary arrays152
733Queue based approach for first non-repeating character in a stream152
734Search in a Binary Search Tree Leetcode Solution151
735Minimum Height Trees151
736Linked List Cycle151
737Find Maximum Depth of Nested Parenthesis in a String151
738Non-decreasing Array LeetCode Solution151
739Find All Duplicates in an Array LeetCode Solution151
740Symmetric Tree Leetcode Solution151
741Minimum Distance Between BST Nodes Leetcode Solution151
742Find unique character in a string151
743Find the largest multiple of 3151
744Largest subarray with equal number of 0s and 1s151
745Race Car LeetCode Solution151
746Remove Duplicates from Sorted List LeetCode Solution150
747Maximum Length of a Concatenated String with Unique Characters Leetcode Solution150
748k-th missing element in increasing sequence which is not present in a given sequence150
749Find Pair with Greatest Product in Array150
750Perform String Shifts Leetcode150
751Minimum Cost For Tickets Leetcode Solution150
752Best Meeting Point LeetCode Solution150
753Bubble sort using two Stacks150
754Word Pattern LeetCode Solution150
755Invert Binary Tree LeetCode Solution150
756First Unique Character in a String LeetCode Solution150
757Generate all possible sorted arrays from alternate elements of two given sorted arrays150
758Binomial Coefficient150
759Check If Array Pairs Are Divisible by k LeetCode Solution150
760Find if Path Exists in Graph Leetcode Solution150
761Maximum 69 Number Leetcode Solution150
762Sorted Linked List to Balanced BST150
763Minimize Maximum Pair Sum in Array LeetCode Solution150
764Binary Tree Maximum Path Sum LeetCode Solution150
765Remove Nth Node From End of List Leetcode Solution150
766Diagonal Traversal of Binary Tree149
767Search a 2D Matrix II Leetcode Solution149
768Morris Traversal149
769Kth ancestor of a node in binary tree149
770Count quadruples from four sorted arrays whose sum is equal to a given value x149
771Find Median from Data Stream LeetCode Solution149
772Elements to be added so that all elements of a range are present in array149
773Maximum Difference Between Increasing Elements LeetCode Solution149
774Growable array based stack149
775Student Attendance Record I Leetcode Solution149
776Merge K Sorted Linked Lists149
777N-Queens LeetCode Solution149
778Evaluate Reverse Polish Notation LeetCode Solution149
779Finding K closest element149
780Jump Game149
781Number of Islands II LeetCode Solution149
782Largest rectangular sub-matrix whose sum is 0148
783Minimum time required to rot all oranges148
784Split a String in Balanced Strings Leetcode Solution148
785Number Complement Leetcode Solution148
786Minimum Time Visiting All Points Leetcode Solution148
787Snakes and Ladders LeetCode Solution148
788Program for Bridge and Torch problem148
789Valid Number148
790Maximum Depth of N-ary Tree Leetcode Solution148
791Remove brackets from an algebraic string containing + and – operators148
792Merge Sorted Array LeetCode Solution147
793Sort an array according to the order defined by another array147
794Special Array With X Elements Greater Than or Equal X Leetcode Solution147
795Transpose Graph147
796Get Maximum in Generated Array Leetcode Solution147
797Nested List Weight Sum II LeetCode Solution147
798Largest Rectangle in Histogram LeetCode Solution147
799Relative Ranks Leetcode Solution147
800Number of NGEs to the Right147
801Minimum number of jumps to reach end147
802Nearest Exit from Entrance in Maze LeetCode Solution147
803Check for Palindrome after every character replacement Query147
804Count items common to both the lists but with different prices147
805Remove Duplicates from Sorted List II147
806Sort Colors146
807Circular Queue146
808Friends Pairing Problem146
809Longest Subarray Having Count of 1s One More than Count of 0s146
810Print a Binary Tree in Vertical Order146
811Tiling Problem146
812Sort Array By Parity II Leetcode Solution146
813Convert BST to Min Heap146
814Minimum Number of Taps to Open to Water a Garden LeetCode Solution146
815One Edit Distance LeetCode Solution146
816Crawler Log Folder Leetcode Solution146
817String comparison containing wildcards146
818A Space Optimized DP solution for 0-1 Knapsack Problem146
819Final Prices With a Special Discount in a Shop Leetcode Solution146
820Base 7 Leetcode Solution146
821Partition to K Equal Sum Subsets Leetcode Solution146
822Reorder Data in Log Files LeetCode Solution145
823Alien Dictionary LeetCode Solution145
824Minimum swaps to make sequences increasing145
825Check if Two Expressions With Brackets are Same145
826Clone Graph LeetCode Solution145
827Subsequence of Size K With the Largest Even Sum LeetCode Solution145
828Subarray Product Less Than K LeetCode Solution145
829Regular Expression Matching145
830Sorted Array to Balanced BST145
831Path with maximum average value145
832Interval Tree145
833Maximum Profit in Job Scheduling Leetcode Solution144
834Iterative Preorder Traversal144
835Partition List Leetcode Solution144
836Course Schedule II – LeetCode144
837Maximum size subarray sum equals k144
838Total Numbers With no Repeated Digits in a Range144
839Minimum Jumps to Reach Home LeetCode Solution144
840Check if a given array can represent Preorder Traversal of Binary Search Tree144
841Minimum Swaps to Make Strings Equal Leetcode Solution144
842Insert into a Binary Search Tree Leetcode Solution144
843Design a Stack With Increment Operation Leetcode Solution144
844Guess Number Higher or Lower LeetCode Solution144
845Make Two Arrays Equal by Reversing Sub-arrays Leetcode Solution144
846Level order Traversal in Spiral Form144
847Last Stone Weight II LeetCode Solution144
848Priority Queue using doubly linked list144
849Find the subarray with least average144
850Minimum Sum Path in a Triangle143
851Can Place Flowers LeetCode Solution143
852Top K Frequent Words LeetCode Solution143
853Count Distinct Elements in Every Window of Size K143
854Subset with sum divisible by m143
855Valid Parentheses Leetcode Solution143
856Permutation Coefficient143
857Find the Only Repetitive Element Between 1 to N-1143
858Brightest Position on Street LeetCode Solution143
859Union and Intersection of two Linked Lists143
860Find all triplets with zero sum143
861Three way partitioning of an array around a given range142
862Check if an Array is Stack Sortable142
863Water Bottles Leetcode Solution142
864Check whether a given Binary Tree is Complete or not142
865Find All Possible Recipes from Given Supplies LeetCode Solution142
866Brick Wall LeetCode Solution142
867Maximum Nesting Depth of the Parentheses Leetcode Solution142
868Given an Array of Pairs Find all Symmetric Pairs in it142
869Repeated Substring Pattern LeetCode Solution141
870Least Number of Unique Integers after K Removals Leetcode Solution141
871Lemonade Change Leetcode Solution141
872Range sum queries without updates141
873Spiral Matrix II Leetcode Solution141
874Count ways to reach the nth stair using step 1, 2 or 3141
875Tree Traversal (Preorder, Inorder & Postorder)141
876Matrix Chain Multiplication141
877Rearrange Spaces Between Words Leetcode Solution141
878Binary Search Tree Search and Insertion141
879LCS (Longest Common Subsequence) of three strings141
880Sum of nearest smaller and greater number141
8814Sum141
882Form Minimum Number From Given Sequence141
883Design Browser History LeetCode Solution141
884Daily Temperatures Leetcode Solution141
885Destination City Leetcode Solution140
886Maximum Score After Splitting a String Leetcode Solution140
887Find all permuted rows of a given row in a matrix140
888An Interesting Method to generate Binary Numbers from 1 to n140
889Distinct adjacent elements in an array140
890GCDs of given index ranges in an array140
891Construct Complete Binary Tree from its Linked List Representation140
892Delete And Earn140
893Count Negative Numbers in a Sorted Matrix LeetCode Solution140
894Shortest Word Distance Leetcode Solution140
895Count Subarrays with Same Even and Odd Elements140
896Insert Delete GetRandom140
897Best Time to Buy and Sell Stock with Transaction Fee Leetcode Solution140
898Guess Number Higher or Lower II140
899Number of Days Between Two Dates LeetCode Solution139
900A program to check if a binary tree is BST or not139
901Missing Element in Sorted Array LeetCode Solution139
902Find Maximum Sum Possible Equal Sum of Three Stacks139
903Check if stack elements are pairwise consecutive139
904Robot Bounded In Circle LeetCode Solution139
905Balanced Expression with Replacement139
906Convert Sorted List to Binary Search Tree139
907Check if the given array can represent Level Order Traversal of Binary Search Tree139
908Identify and Mark Unmatched Parenthesis in an Expression139
909Sequences of given length where every element is more than or equal to twice of previous139
910Diagonal Traversal LeetCode Solution139
911Set Matrix Zeroes Leetcode Solution139
912Queries for GCD of all numbers of an array except elements in a given range139
913Rearrange an Array Such that arr[i] is equal to i139
914Time Based Key-Value Store LeetCode Solution139
915BFS for Disconnected Graph138
916Diagonal Traverse LeetCode Solution138
917Find Common Characters Leetcode Solution138
918Range LCM Queries138
919Vertical sum in a given binary tree138
920Special Positions in a Binary Matrix Leetcode Solution138
921Alien Dictionary138
922Find distance between two nodes of a Binary Tree138
923Minimum sum of multiplications of n numbers138
924Palindrome Partitioning Leetcode Solution138
925Number of Distinct Islands Leetcode Solution137
926Remove Duplicates from Sorted List II LeetCode Solution137
927Merging Intervals137
928Longest Palindromic Subsequence137
929Stone Game II Leetcode137
930Analyze User Website Visit Pattern LeetCode Solution137
931Rearrange Array such that arr[i] >= arr[j] if i is even and arr[i] <= arr[j] if i is odd and j < i137
932Spiral Matrix III LeetCode Solution137
933Merge Two Sorted Lists Leetcode137
934Averages of Levels in Binary Tree136
935K’th Largest Element in BST when modification to BST is not allowed136
936Queue using Stacks136
9373 Sum136
938Construct the Rectangle Leetcode Solution136
939Number of Equivalent Domino Pairs Leetcode Solution136
940Can Make Arithmetic Progression From Sequence Leetcode Solution136
941Maximum Frequency Stack Leetcode Solution136
942Intersection of Two Linked Lists LeetCode Solution136
943Lexicographical Numbers Leetcode Solution136
944Infix to Postfix136
945Sliding Window Maximum136
946Print Fibonacci sequence using 2 variables136
947Maximum Subarray Sum Excluding Certain Elements136
948Maximize Sum of Array after K Negations Leetcode Solution136
949Three Consecutive Odds Leetcode Solution136
950Breadth First Search (BFS) for a Graph135
951Difference Array | Range update query in O(1)135
952Minimum Height Trees LeetCode Solution135
953Construct BST from its given Level Order Traversal135
954Binary array after M range toggle operations135
955Count Submatrices With All Ones LeetCode Solution135
956Binary Tree Longest Consecutive Sequence LeetCode Solution135
957All Unique Triplets that Sum up to a Given Value135
958Pattern Occurrences using Stack135
959Dividing Array into Pairs With Sum Divisible by K135
960Trim a Binary Search Tree135
961Median of Two Sorted Arrays135
962Largest area rectangular sub-matrix with equal number of 1’s and 0’s135
963Check if any two intervals overlap among a given set of intervals134
964Largest divisible pairs subset134
965Strongly Connected Component134
966Word Break134
967Reverse Nodes in K-Group134
968Check If a Word Occurs As a Prefix of Any Word in a Sentence Leetcode Solution134
969Palindrome Partitioning134
970Largest Substring Between Two Equal Characters Leetcode Solution134
971Height of a generic tree from parent array134
972Find Maximum of Minimum for Every Window Size in a Given Array134
973Find postorder traversal of BST from preorder traversal134
974Newman-Conway Sequence134
975Symmetric Tree133
976Segment Tree133
977Iterative Postorder Traversal Using Two Stacks133
978Binary Search Tree Delete Operation133
979Depth First Search (DFS) for a Graph133
980Kth Smallest Element in a BST Leetcode Solution133
981Product of Array Except Self LeetCode Solution133
982Shuffle 2n integers as a1-b1-a2-b2-a3-b3-..bn without using extra space133
983Split Array Into Consecutive Subsequences133
984Create Maximum Number133
985First missing positive133
986Maximum Product Subarray133
987Length of Longest Fibonacci Subsequence132
988My Calendar I LeetCode Solution132
989Find Duplicate Subtrees132
990Level Order Traversal of Binary Tree132
991Climbing stairs132
992Maximum subsequence sum such that no three are consecutive132
993Rearrange array such that even positioned are greater than odd132
994Asteroid Collision LeetCode Solution132
995The Maze III LeetCode Solution132
996Boundary Traversal of binary tree132
997Minesweeper LeetCode Solution132
998Sign of the Product of an Array LeetCode Solution132
999Count pair with Given Sum132
1000Count Primes in Ranges132
1001Longest subsequence such that difference between adjacents is one131
1002Decrypt String from Alphabet to Integer Mapping Leetcode Solution131
1003Find the First Circular Tour that visits all the Petrol Pumps131
1004Kill Process LeetCode Solution131
1005Double the first element and move zero to end131
1006Longest Nice Substring LeetCode Solution131
1007Partition Equal Subset Sum131
1008Unique Paths II131
1009K Closest Points to Origin Leetcode Solution131
1010Serialize and Deserialize Binary Tree131
1011Find the Difference Leetcode Solution131
1012Maximum Number of Ways to Partition an Array LeetCode Solution131
1013Make The String Great Leetcode Solution131
1014Graph Valid Tree LeetCode Solution130
1015Insertion in a Binary Tree130
1016Maximum Length of Repeated Subarray130
1017The Painter’s Partition Problem130
1018Largest Number Leetcode Solution130
1019Find number of pairs in an array such that their XOR is 0130
1020Level order traversal using two Queues130
1021Shortest Completing Word Leetcode Solution130
1022Valid Boomerang Leetcode Solution130
1023Next Greater Element III LeetCode Solution130
1024Super Ugly Number130
1025Count subarrays where second highest lie before highest129
1026Compute nCr % p129
1027Number Of Longest Increasing Subsequence129
1028Design Hit Counter LeetCode Solution129
1029Friends Of Appropriate Ages LeetCode Solution129
1030Collect maximum points in a grid using two traversals129
1031Ugly Number II LeetCode Solution129
1032Advantages of BST over Hash Table129
1033Balanced Binary Tree129
1034Binary Search Tree129
1035Scramble String LeetCode Solution128
1036Defanging an IP Address LeetCode Solution128
1037Kth Smallest Element in a Sorted Matrix LeetCode Solution128
1038Employee Importance LeetCode Solution128
1039Implement Trie (Prefix Tree) Leetcode Solution128
1040Ugly Numbers128
1041Invalid Transactions LeetCode Solution128
1042Build an Array With Stack Operations Leetcode Solution128
1043String Matching in an Array Leetcode Solution128
1044Available Captures for Rook Leetcode Solution128
1045Rearrange an array such that ‘arr[j]’ becomes ‘i’ if ‘arr[i]’ is ‘j’128
1046Boolean Parenthesization Problem128
1047Morris Inorder Traversal128
1048Maximum Product of Indexes of Next Greater on Left and Right128
1049Move all negative elements to end in order with extra space allowed128
1050Construction of Longest Increasing Subsequence (N log N)128
1051Number of palindromic paths in a matrix128
1052Construct Binary Tree from given Parent Array representation128
1053Minimum Size Subarray Sum128
1054Regular Expression Matching Regular Expression Matching LeetCode Solution127
1055Find Peak Element127
1056Maximum length subsequence with difference between adjacent elements as either 0 or 1127
1057Find whether a subarray is in form of a mountain or not127
1058Maximum Sum of 3 Non-Overlapping Subarrays127
1059Minimum Index Sum of Two Lists127
1060Count minimum steps to get the given desired array127
1061Add two numbers127
1062Maximum difference between frequency of two elements such that element having greater frequency is also greater127
1063Populating Next Right Pointers in Each Node Leetcode Solution127
1064Maximum weight transformation of a given string127
1065Longest Bitonic Subsequence127
1066Generate Parentheses Leetcode Solution126
1067Find the minimum distance between two numbers126
1068Validate Binary Search Tree126
1069Iterative Depth First Traversal of Graph126
1070Lowest Common Ancestor126
1071Bitwise AND of Numbers Range LeetCode Solution126
1072Remove Duplicates from Sorted Array II Leetcode Solution126
1073Recover Binary Search Tree Leetcode Solution126
1074Find a Peak Element II LeetCode Solution126
1075Combination Sum IV LeetCode Solution126
1076Divisible Pairs Counting126
1077Custom Sort String Leetcode Solution126
1078Day of the Year Leetcode Solution125
1079Determine Whether Matrix Can Be Obtained By Rotation LeetCode Solution125
1080Number of Closed Islands Leetcode Solution125
1081Path Sum II LeetCode Solution125
1082Maximize Distance to Closest Person LeetCode Solution125
1083Binary Tree Right Side View LeetCode Solution125
1084Search in Sorted Rotated Array125
1085Binary Tree Data Structure125
1086Smallest Common Region Leetcode Solution125
1087Largest BST Subtree LeetCode Solution125
1088Types of Binary Tree124
1089Consecutive Characters LeetCode Solution124
1090Path Sum124
1091Kth Smallest Product of Two Sorted Arrays LeetCode Solution124
1092Print all triplets in sorted array that form AP124
1093Subarrays with K Different Integers Leetcode Solution124
1094Next Permutation Leetcode Solution124
1095Number of Students Doing Homework at a Given Time Leetcode Solution124
1096Clone a Binary Tree with Random Pointers124
1097Rearrange array such that even index elements are smaller and odd index elements are greater124
1098Remove Palindromic Subsequences Leetcode Solution124
1099Find Smallest Range Containing Elements from k Lists124
1100Level of Each node in a Tree from source node124
1101Increasing Triplet Subsequence LeetCode Solution124
1102Print Next Greater Number of Q queries124
1103Count pairs from two sorted arrays whose sum is equal to a given value x123
1104Topological Sorting123
1105Distinct Subsequences123
1106Serialize and Deserialize Binary Tree LeetCode Solution123
1107Number of siblings of a given Node in n-ary Tree123
1108Remove duplicates from sorted array122
1109Bottom View of a Binary Tree122
1110Root to Leaf path with target sum Leetcode Solutions122
1111Cutting a Rod122
1112Maximum Product Subarray122
1113Third Maximum Number Leetcode Solution122
1114Constant time range add operation on an array122
1115Find maximum difference between nearest left and right smaller elements122
1116Valid Tic-Tac-Toe State LeetCode Solution121
1117Count Largest Group Leetcode Solution121
1118Write Code to Determine if Two Trees are Identical121
1119Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution121
1120Maximum Binary Tree121
1121Print Right View of a Binary Tree121
1122Minimum Score Triangulation of Polygon Leetcode Solution121
1123Mean of Array After Removing Some Elements Leetcode Solution121
1124Find Three Element From Different Three Arrays Such That a + b + c = sum121
1125Convert BST into a Min-Heap without using array121
1126Search Insert Position120
1127Products of ranges in an array120
1128Cells with Odd Values in a Matrix LeetCode Solution120
1129Minimum sum of squares of character counts in a given string after removing k characters120
1130Longest Subarray of 1’s After Deleting One Element LeetCode Solution120
1131Search an Element in Sorted Rotated Array120
1132Palindrome Permutation LeetCode Solution120
1133Golomb sequence120
1134Minimum Absolute Difference in BST Leetcode Solution120
1135Iterative method to find ancestors of a given binary tree120
1136Reformat The String Leetcode Solution120
1137Queries for Number of Distinct Elements in a Subarray120
1138Find a sorted subsequence of size 3 in linear time119
1139Construct K Palindrome Strings LeetCode Solution119
1140Sum of Even Numbers After Queries119
1141Moser-de Bruijn Sequence119
1142Longest Increasing Consecutive Subsequence119
1143Red-Black Tree Introduction119
1144Closest Binary Search Tree Value Leetcode Solution119
1145Thousand Separator Leetcode Solution119
1146Print modified array after executing the commands of addition and subtraction119
1147Prime Palindrome LeetCode Solution119
1148Delete Nodes and Return Forest Leetcode Solution118
1149Factorial Trailing Zeroes LeetCode Solution118
1150Maximum Product of Splitted Binary Tree LeetCode Solution118
1151Find maximum length Snake sequence118
1152Bus Routes Leetcode Solution118
1153Binary Tree to Binary Search Tree Conversion118
1154Merge two BSTs with limited extra space118
1155Transform a BST to Greater sum Tree118
1156Find the smallest binary digit multiple of given number117
1157Number of Orders in the Backlog Leetcode Solution117
1158K’th Largest element in BST using constant extra space117
1159K maximum sums of overlapping contiguous sub-arrays117
1160Count even length binary sequences with same sum of first and second half bits117
1161Possible Bipartition LeetCode Solution117
1162Check Array Formation Through Concatenation Leetcode Solution117
1163Decision Tree117
1164Kth Smallest Number in Multiplication Table Leetcode Solution117
1165Swap Nodes In Pairs117
1166Find Two Non-overlapping Sub-arrays Each With Target Sum LeetCode Solution117
1167Longest Repeated Subsequence117
1168Palindromic Substrings Leetcode Solution117
1169Swapping Nodes in a Linked List Leetcode Solution116
1170Subset Sum Problem in O(sum) space116
1171Maximize sum of consecutive differences in a circular array116
1172Minimum Sideway Jumps LeetCode Solution116
1173Rotate Array116
1174Compare Strings by Frequency of the Smallest Character Leetcode Solution116
1175Minimum Cost to Move Chips to The Same Position LeetCode Solution116
1176Priority Queue116
1177Web Crawler LeetCode Solution116
1178Minimum Moves to Equal Array Elements LeetCode Solution116
1179First Bad Version115
1180Closest Leaf in a Binary Tree LeetCode Solution115
1181Find Largest Value in Each Tree Row LeetCode Solution115
1182Search Suggestions System LeetCode Solution115
1183Given a binary tree, how do you remove all the half nodes?114
1184Remove Max Number of Edges to Keep Graph Fully Traversable Leetcode Solution114
1185Decrease Elements To Make Array Zigzag LeetCode Solution114
1186Count Pairs Whose Products Exist in Array114
1187Queue Reconstruction by Height114
1188Diameter of N-Ary Tree LeetCode Solution114
1189Matchsticks to Square Leetcode Solution113
1190Reverse a Path in BST using Queue113
1191Convert Sorted Array to Binary Search Tree LeetCode Solutions113
1192Contiguous Array LeetCode Solution113
1193Kth Smallest Element in a BST113
1194Maximum number of segments of lengths a, b and c113
1195Moving Stones Until Consecutive Leetcode Solution113
1196Maximum Depth Of Binary Tree112
1197Sum of Left Leaves LeetCode Solution112
1198Reformat Date LeetCode Solution112
1199Lowest Common Ancestor in Binary Search Tree112
1200Write a function to get the intersection point of two Linked Lists112
1201Valid Triangle Number112
1202Filter Restaurants by Vegan-Friendly, Price and Distance Leetcode Solution112
1203Champagne Tower LeetCode Solution112
1204Array Queries for multiply replacements and product112
1205Maximum sum bitonic subarray112
1206New 21 Game111
1207Range Queries for Longest Correct Bracket Subsequence111
1208Maximum sum of pairs with specific difference111
1209Integer Break LeetCode Solution111
1210Range Sum Query using Sparse Table111
1211How to print maximum number of A’s using given four keys111
1212Replace two consecutive equal values with one greater111
1213Maximum Value at a Given Index in a Bounded Array LeetCode Solution110
1214Valid Perfect Square LeetCode Solution110
1215Graph and its representation110
1216Divide Two Integers Leetcode Solution110
1217Guess The Word110
1218Concatenation of Array LeetCode Solution110
1219Convert Integer to the Sum of Two No-Zero Integers Leetcode Solution110
1220Symmetric Tree LeetCode Solution Leetcode Solution110
1221Path Crossing Leetcode Solution110
1222Design Skiplist LeetCode Solution110
1223Merge Sort109
1224BST to a Tree with Sum of all Smaller Keys109
1225Lowest Common Ancestor of a Binary Tree Leetcode Solution109
1226Print modified array after multiple array range increment operations109
1227Maximum sum of a path in a Right Number Triangle109
1228Check for Identical BSTs without building the trees109
1229Perfect Squares LeetCode Solution109
1230Arithmetic Slices II – Subsequence LeetCode Solution109
1231Check if each internal node of a BST has exactly one child109
1232Check Completeness of a Binary Tree LeetCode Solution109
1233The kth Factor of n Leetcode Solution109
1234Flatten 2D Vector LeetCode Solution109
1235Check if all levels of two Binary Tree are anagrams or not108
1236Power of Two108
1237Minimum Swaps To Make Sequences Increasing LeetCode Solution108
1238Count Subsets Having Distinct Even Numbers108
1239LRU Cache Leetcode Solution108
1240Longest Common Prefix Using Word by Word Matching108
1241Queries on Probability of Even or Odd Number in given Ranges108
1242Parallel Courses II LeetCode Solution108
1243Sliding Window Median Leetcode Solution108
1244Image Overlap LeetCode Solution107
1245Maximum Array from Two given Arrays Keeping Order Same107
1246Mean of range in array107
1247Missing Number107
1248Find Minimum in Rotated Sorted Array II LeetCode Solution107
1249Graph Cloning107
1250Largest Plus Sign Leetcode Solution107
1251Contiguous Array107
1252Maximize Elements Using Another Array107
1253Count and Toggle Queries on a Binary Array107
1254Bold Words in String LeetCode Solution106
1255Maximum Product Subarray106
1256Print n terms of Newman-Conway Sequence106
1257Find minimum number of merge operations to make an array palindrome106
1258Check If a String Can Break Another String Leetcode Solution106
1259Minimum Remove to Make Valid Parentheses LeetCode Solution105
1260Excel Sheet Column Title LeetCode Solution105
1261Verify Preorder Serialization of a Binary Tree105
1262Find k-th smallest element in BST (Order Statistics in BST)105
1263Merge k Sorted Lists Leetcode Solution104
1264Print Ancestors of a Given Binary Tree Node Without Recursion104
1265Next greater element104
1266Smallest Range II Leetcode Solution103
1267Minimum Time to Collect All Apples in a Tree LeetCode Solution103
1268Palindrome Partitioning103
1269Check if two nodes are on the same path in a Tree102
1270Min Cost Climbing Stairs LeetCode Solution102
1271Merge Sorted Array101
1272Check in binary array the number represented by a subarray is odd or even101
1273Orderly Queue LeetCode Solution101
1274Koko Eating Bananas LeetCode Solution100
1275Peeking Iterator LeetCode Solution100
1276Check if X can give change to every person in the Queue99
1277Newman–Shanks–Williams prime99
1278Number of elements less than or equal to a given number in a given subarray99
1279Different Ways to Add Parentheses Leetcode Solution99
1280Longest Substring Without Repeating Characters Leetcode Solution97
1281Range Minimum Query (Square Root Decomposition and Sparse Table)97
1282Largest Submatrix With Rearrangements LeetCode Solution97
1283Maximum Sum Increasing Subsequence97
1284Find maximum average subarray of k length97
1285Queries for Decimal Values of Subarrays of a Binary Array96
1286Number of indexes with equal elements in given range96
1287Minimum Total Space Wasted With K Resizing Operations LeetCode Solution95
1288Maximum product of an increasing subsequence95
1289Array Nesting Leetcode Solution95
1290Binary Tree to Binary Search Tree Conversion using STL set94
1291Check given array of size n can represent BST of n levels or not94
1292Arranging Coins Leetcode Solution93
1293Minimum Number of People to Teach LeetCode Solution93
1294Reach a Number LeetCode Solution92
1295Convert to Base -2 LeetCode Solution92
1296Queries on XOR of greatest odd divisor of the range92
1297Encoded String With Shortest Length LeetCode Solution92
1298Jump Game IV LeetCode Solution92
1299Random Pick Index LeetCode Solution92
1300Find the Winner of the Circular Game LeetCode Solution92
1301Convert a BST to a Binary Tree such that sum of all greater keys is added to every key91
1302Minimum Possible Integer After at Most K Adjacent Swaps On Digits LeetCode Solution91
1303Insert Delete GetRandom O(1) Leetcode Solution90
1304Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution88
1305Palindrome Number LeetCode Solution88
1306Add Two Numbers II Leetcode Solution87
1307Vertical Order Traversal of Binary Tree LeetCode Solution87
1308Design Underground System Leetcode Solution86
1309Continuous Subarray Sum LeetCode Solution85
1310Print Maximum Length Chain of Pairs84
1311Detect Capital Leetcode Solution81
1312Design A Leaderboard Leetcode Solution79
1313Top K Frequent Elements LeetCode Solution79
1314Substring with Concatenation of All Words Leetcode Solution78
1315Minimum Swaps to Group All 1’s Together Leetcode Solution77
1316Decode String Leetcode Solution74
1317Minimum Path Sum Leetcode Solution74
1318Odd Even Linked List Leetcode Solution72
1319Binary Tree Inorder Traversal LeetCode Solution72
1320Count Sub Islands LeetCode Solution72
1321Shortest Unsorted Continuous Subarray LeetCode Solution71
1322Shifting Letters LeetCode Solution71
1323Best Meeting Point LeetCode Solution70
1324Find the Town Judge LeetCode Solution70
1325Sum Root to Leaf Numbers LeetCode Solution70
1326Maximum Population Year LeetCode Solution70
1327Longest Common Subsequence LeetCode Solution68
1328Find the Town Judge LeetCode Solution68
1329Design Add and Search Words Data Structure LeetCode Solution67
1330Score of Parenthesis LeetCode Solution65
1331Rectangle Overlap LeetCode Solution65
1332Maximum Population Year LeetCode Solution65
1333Insert into a Sorted Circular Linked List LeetCode Solution62
1334Flatten Binary Tree to Linked List LeetCode Solution62
1335Stone Game IV LeetCode Solution62
1336Range Sum Query 2D – Immutable LeetCode Solution60
1337Is Graph Bipartite? LeetCode Solution60
1338Valid Triangle Number LeetCode Solution59
1339Reveal Cards In Increasing Order Leetcode Solution54
1340Divide Chocolate LeetCode Solution50
1341Range Sum of BST LeetCode Solution43
1342Step-By-Step Directions From a Binary Tree Node to Another LeetCode Solution42
1343Reverse Integer Leetcode Solution40
1344Sort Colors LeetCode Solution37
1345Find K Closest Elements LeetCode Solution34
1346Excel Sheet Column Number LeetCode Solution33
1347Rotate String LeetCode Solution32
1348Maximum Side Length of a Square with Sum Less than or Equal to Threshold LeetCode Solution31
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