Count Good Nodes in Binary Tree LeetCode Solution


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Problem Statement:

Count Good Nodes in Binary Tree LeetCode Solution:

Given a binary tree root, a node X in the tree is named good if in the path from the root to X there are no nodes with a value greater than X.

Return the number of good nodes in the binary tree.

 

Example 1:

Count Good Nodes in Binary Tree LeetCode SolutionPin

Input:

 root = [3,1,4,3,null,1,5]

Output:

 4

Explanation: Nodes in blue are good. Root Node (3) is always a good node. Node 4 -> (3,4) is the maximum value in the path starting from the root. Node 5 -> (3,4,5) is the maximum value in the path Node 3 -> (3,1,3) is the maximum value in the path.

Example 2:

Count Good Nodes in Binary Tree LeetCode Solution:Pin

Input:

 root = [3,3,null,4,2]

Output:

 3

Explanation:  Node 2 -> (3, 3, 2) is not good, because “3” is higher than it.

Example 3:

Input:

 root = [1]

Output:

 1

Explanation: Root is considered as good.

Constraints:

  • The number of nodes in the binary tree is in the range [1, 10^5].
  • Each node’s value is between [-10^4, 10^4].

Approach:

Idea:

  1. This problem can be solved using the iterative way and also the recursive way. Let’s look into the recursive way as it is easy.
  2. we will traverse the right subtree and left subtree recursive manner.
  3. Update the maximum value found while recursing down to the paths from the root to the leaves.
  4. If node value >= current maximum, we will increase our cnt value.
  5. When the node will be null we will simply end our recursion call.
  6. Total cnt will be our estimated answer.

Code:

Count Good Nodes in Binary Tree C++ Code:

class Solution {
public:
    void Count(TreeNode* root,int &count,int maxi){
        if(root==NULL) return;
        if(root->val >= maxi){count++; maxi=max(maxi,root->val);}
        Count(root->left,count,maxi);
        Count(root->right,count,maxi);
        return;
        
}
    int goodNodes(TreeNode* root){
        int count=0;
        int maxi=root->val;
        Count(root,count,maxi);
        return count;
    }
};

Count Good Nodes in Binary Tree Java Code:

class Solution {
    int cnt=0;
    void rec(TreeNode root,int val)
    {
        
        if(root==null)
            return ;
        if(root.val>=val)
            cnt++;
        int k=Math.max(val,root.val);
        rec(root.left,k);
        rec(root.right,k);
    }
    public int goodNodes(TreeNode root) {
         int val=Integer.MIN_VALUE;
        rec(root,val);
        return cnt;
    }
}

Complexity Analysis of Count Good Nodes in Binary Tree Leetcode Solution:

Time Complexity:

Time complexity will be O(n). Where n is the number of nodes, we are visiting every node only once.

Space Complexity:

We are not taking any extra space. So, space complexity will be O(1).

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582Number of Provinces Leetcode Solution209
583Build Array From Permutation Leetcode Solution209
5843Sum Closest LeetCode Solution209
585Maximum difference between first and last indexes of an element in array209
586Implementation of Deque using circular array209
587Best Time to Buy and Sell Stock209
588Longest Increasing Subsequence209
589Non-overlapping sum of two sets209
590Shortest Path in a Grid with Obstacles Elimination LeetCode Solution209
591Find Words That Can Be Formed by Characters Leetcode Solution208
592Distribute Candies to People Leetcode Solution208
593Frog Jump Leetcode Solution208
594Delete consecutive same words in a sequence208
595Rotate Image LeetCode Solution208
596Relative Sort Array Leetcode Solution208
597Maximum Number of Occurrences of a Substring Leetcode Solution208
598Decode Ways208
599Combinations Leetcode Solution208
600Trapping Rain Water LeetCode Solution207
601Remove All Occurrences of a Substring LeetCode Solution207
602Island Perimeter Leetcode Solution207
603Sort Characters By Frequency LeetCode Solution207
604First negative integer in every window of size k207
605Iterative Method to find Height of Binary Tree207
60601 Matrix LeetCode Solution207
607Minimum Operations to convert X to Y207
608Remove Linked List Elements Leetcode Solution206
609Sum of f(a[i], a[j]) over all pairs in an array of n integers206
610LRU Cache LeetCode Solution206
611Minimum number of distinct elements after removing m items205
612GCD Of Two Numbers205
613Maximum Number of Chocolates to be Distributed Equally Among k Students205
614Minimum insertions to form a palindrome with permutations allowed205
615Find minimum difference between any two elements205
616The Knapsack Problem205
617Reverse a stack without using extra space in O(n)205
618Bubble sort using two Stacks204
619Assign Cookies Leetcode Solution204
620Find the smallest positive integer value that cannot be represented as sum of any subset of a given array204
621Rotate List Leetcode Solution204
622Count all subsequences having product less than K204
623XOR Operation in an Array Leetcode Solution204
624Tracking current Maximum Element in a Stack203
625Permutation in String Leetcode Solution203
626Isomorphic Strings203
627Unique Binary Search Trees203
628Reorganize String203
629How to Create Mergable Stack?203
630Convert an array to reduced form203
631Insert Interval Leetcode Solution203
632Convert Sorted Array to Binary Search Tree Leetcode Solution202
633Form minimum number from given sequence202
634K Empty Slots202
635Find Largest d in Array such that a + b + c = d202
636Stone Game LeetCode202
637Longest Increasing Path in a Matrix LeetCode Solution202
638Find the Duplicate Number LeetCode Solution202
639Employee Free Time LeetCode Solution201
640Distance Between Bus Stops Leetcode Solution201
641Find Pair with Greatest Product in Array201
642Same Tree LeetCode Solution201
643Largest subarray with equal number of 0s and 1s201
644Defanging an IP Address Leetcode Solution201
645Applications of Breadth First Search and Depth First Search201
646Count Good Nodes in Binary Tree Leetcode Solution200
647License Key Formatting Leetcode Solution200
648Optimal Account Balancing LeetCode Solution200
649First Unique Character in a String LeetCode Solution200
650Find the node with minimum value in a Binary Search Tree200
651Maximum Consecutive Numbers Present in an Array199
652Valid Palindrome199
653Minimum Depth of Binary Tree Leetcode Solution199
654Word Wrap Problem199
655Letter Combinations of a Phone Number199
656Convert a Number to Hexadecimal Leetcode Solution199
657Printing brackets in Matrix Chain Multiplication Problem199
658Merge Two Balanced Binary Search Trees199
659Coin Change Problem199
660Robot Room Cleaner Leetcode Solution198
661Find pairs with given sum such that elements of pair are in different rows198
662Replace Elements with Greatest Element on Right Side Leetcode Solution198
663Longest Span with same Sum in two Binary arrays198
664Painting Fence Algorithm197
665Check If It Is a Straight Line Leetcode Solution197
666Numbers with prime frequencies greater than or equal to k197
667Find the Distance Value Between Two Arrays Leetcode Solution197
668House Robber197
669Flipping an Image LeetCode Solution197
670Longest Substring with At Most K Distinct Characters LeetCode Solution197
671Kth Missing Positive Number Leetcode Solution197
672Minimum Number of Steps to Make Two Strings Anagram Leetcode Solutions197
673K Empty Slots LeetCode197
674Sort Array By Parity LeetCode Solution197
675Reducing Dishes LeetCode Solution196
676Partition Labels LeetCode Solution196
677String to Integer (atoi) LeetCode Solution196
678Distance of nearest cell having 1 in a binary matrix196
679k-th missing element in increasing sequence which is not present in a given sequence196
680Number of Dice Rolls With Target Sum LeetCode Solution196
681Strobogrammatic Number LeetCode Solution196
682Moving Average from Data Stream Leetcode Solution196
683Count quadruples from four sorted arrays whose sum is equal to a given value x196
684Segregate 0s and 1s in an Array196
685Maximum Product of Two Elements in an Array Leetcode Solution196
686Reservoir Sampling196
687Print the Fibonacci numbers in reverse order195
688String Compression LeetCode Solution195
689Longest Substring with At Least K Repeating Characters LeetCode Solution195
690Valid Palindrome II Leetcode Solution195
691Power of Four Leetcode Solution195
692Generate all possible sorted arrays from alternate elements of two given sorted arrays195
693Dynamic Programming Basics194
694Reverse Only Letters LeetCode Solution194
695Queries for counts of array elements with values in given range194
696Partition Array Into Three Parts With Equal Sum Leetcode Solution194
697Find Maximum Level sum in Binary Tree194
698Find unique character in a string194
699Find Leaves of Binary Tree LeetCode Solution194
700Find the largest multiple of 3193
701Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest193
702Remove Invalid Parentheses Leetcode Solution193
703Snakes and Ladders LeetCode Solution193
704Best Time to Buy and Sell Stock with Cooldown Leetcode Solution193
705Binary Tree Maximum Path Sum LeetCode Solution193
706Increasing Decreasing String Leetcode Solution193
707Find whether an array is subset of another array193
708Sum of All Odd Length Subarrays Leetcode Solution193
709Remove brackets from an algebraic string containing + and – operators192
710Check for Palindrome after every character replacement Query192
711Path With Maximum Minimum Value LeetCode Solution192
712Unique Paths II Leetcode Solution192
713To Lower Case Leetcode Solution192
714Stack Permutations (Check if an array is stack permutation of other)192
715Growable array based stack192
716Elements to be added so that all elements of a range are present in array192
717Check If Two String Arrays are Equivalent Leetcode Solution192
718Find the Smallest Divisor given a Threshold Leetcode Solution192
719Wiggle Sort192
720Find Maximum Depth of Nested Parenthesis in a String191
721Lucky Numbers in a Matrix Leetcode Solution191
722Sort Array by Increasing Frequency Leetcode Solution191
723Edit Distance LeetCode Solution191
724Inorder Successor of a node in Binary Tree191
725Valid Perfect Square Leetcode Solution191
726Keyboard Row Leetcode Solution191
727Bulb Switcher LeetCode Solution191
728Binary Tree zigzag level order Traversal191
729Populating Next Right Pointers in Each Node191
730Maximum Number of Coins You Can Get Leetcode Solution191
731Merge Sorted Array LeetCode Solution190
732Base 7 Leetcode Solution190
733Minimum Cost For Tickets Leetcode Solution190
734String comparison containing wildcards190
735BFS vs DFS for Binary Tree190
736Non-decreasing Array LeetCode Solution190
737Majority Element II Leetcode Solution190
738Valid Number190
739Number of NGEs to the Right190
740Merge Two Binary Trees LeetCode Solution190
741Factorial Trailing Zeroes Leetcode Solution190
742Priority Queue using doubly linked list190
743Recover Binary Search Tree190
744Reversing a Queue using Recursion190
745Subset Sum Leetcode190
746Race Car LeetCode Solution190
747Ugly Number Leetcode Solution190
748Binary Tree Zigzag Level Order Traversal LeetCode Solution190
749Delete Nth node from the end of the given linked list190
750Permutation Sequence LeetCode Solution190
751Print a Binary Tree in Vertical Order189
752Tiling Problem189
753Maximum Length of a Concatenated String with Unique Characters Leetcode Solution189
754Perform String Shifts Leetcode189
755Find if Path Exists in Graph Leetcode Solution189
756Student Attendance Record I Leetcode Solution188
757Check if Two Expressions With Brackets are Same188
758Program for Bridge and Torch problem188
759Finding K closest element188
760Maximum 69 Number Leetcode Solution188
761Morris Traversal188
762Regular Expression Matching188
763Minimum sum of multiplications of n numbers188
764Restore IP Addresses Leetcode Solution188
765Maximum Profit in Job Scheduling Leetcode Solution188
766Longest Subarray Having Count of 1s One More than Count of 0s188
767Count items common to both the lists but with different prices188
768Best Meeting Point LeetCode Solution188
769Maximum Product of Three Numbers LeetCode Solution187
770Partition to K Equal Sum Subsets Leetcode Solution187
771Number of Days Between Two Dates LeetCode Solution187
772Add and Search Word – Data structure design LeetCode187
773Construct BST from given Preorder Traversal187
774N-Queens LeetCode Solution187
775Word Pattern LeetCode Solution187
776Circular Queue187
777Minimum Distance Between BST Nodes Leetcode Solution187
778Split a String in Balanced Strings Leetcode Solution187
779Evaluate Reverse Polish Notation LeetCode Solution187
780Check If Array Pairs Are Divisible by k LeetCode Solution186
781Minimum Time Visiting All Points Leetcode Solution186
782Sort an array according to the order defined by another array186
783Minimum Height Trees186
784Binomial Coefficient186
785Find All Duplicates in an Array LeetCode Solution186
786Top K Frequent Words LeetCode Solution186
787Find Median from Data Stream LeetCode Solution186
788Jump Game186
789Hamming Distance Leetcode Solution186
790Symmetric Tree Leetcode Solution186
791Rank Transform of an Array Leetcode Solution186
792Form Minimum Number From Given Sequence186
793Decompress Run-Length Encoded List Leetcode Solution186
794Largest Rectangle in Histogram LeetCode Solution186
795Find All Possible Recipes from Given Supplies LeetCode Solution185
796Invert Binary Tree LeetCode Solution185
797Minimize Maximum Pair Sum in Array LeetCode Solution185
798Maximum Depth of N-ary Tree Leetcode Solution185
799Sorted Linked List to Balanced BST185
800Brick Wall LeetCode Solution185
801Nested List Weight Sum II LeetCode Solution185
802Total Numbers With no Repeated Digits in a Range184
803Linked List Cycle184
804Maximum Nesting Depth of the Parentheses Leetcode Solution184
805Merge K Sorted Linked Lists184
806Find all permuted rows of a given row in a matrix184
807Special Array With X Elements Greater Than or Equal X Leetcode Solution184
808Identify and Mark Unmatched Parenthesis in an Expression184
809Queue based approach for first non-repeating character in a stream184
810Search in a Binary Search Tree Leetcode Solution184
811Largest rectangular sub-matrix whose sum is 0183
812Balanced Expression with Replacement183
813Crawler Log Folder Leetcode Solution183
814Remove Nth Node From End of List Leetcode Solution183
815Nearest Exit from Entrance in Maze LeetCode Solution183
816Number of Islands II LeetCode Solution183
817Kth ancestor of a node in binary tree183
818Maximum Difference Between Increasing Elements LeetCode Solution182
819Minimum Swaps to Make Strings Equal Leetcode Solution182
820Course Schedule II – LeetCode182
821Interval Tree182
822Transpose Graph182
823Minimum time required to rot all oranges182
824Given an Array of Pairs Find all Symmetric Pairs in it182
825Repeated Substring Pattern LeetCode Solution182
826Split Array Into Consecutive Subsequences182
827Diagonal Traversal of Binary Tree182
828Relative Ranks Leetcode Solution182
829One Edit Distance LeetCode Solution182
830A Space Optimized DP solution for 0-1 Knapsack Problem181
831Find Maximum Sum Possible Equal Sum of Three Stacks181
832Brightest Position on Street LeetCode Solution181
833Final Prices With a Special Discount in a Shop Leetcode Solution181
834Deletion in a Binary Tree181
835Insert Delete GetRandom181
836Minimum Number of Taps to Open to Water a Garden LeetCode Solution181
837Permutation Coefficient181
838Lemonade Change Leetcode Solution180
839Subsequence of Size K With the Largest Even Sum LeetCode Solution180
840Check if stack elements are pairwise consecutive180
841Search a 2D Matrix II Leetcode Solution180
842Remove Duplicates from Sorted List II180
843Reorder Data in Log Files LeetCode Solution180
844Subarray Product Less Than K LeetCode Solution180
845Tree Traversal (Preorder, Inorder & Postorder)180
846Design Browser History LeetCode Solution180
847Last Stone Weight II LeetCode Solution180
848Path with maximum average value180
849LCS (Longest Common Subsequence) of three strings179
850Sort Array By Parity II Leetcode Solution179
851Binary Search Tree Search and Insertion179
852Sliding Window Maximum179
853Minimum Jumps to Reach Home LeetCode Solution179
854Clone Graph LeetCode Solution179
855Missing Element in Sorted Array LeetCode Solution179
856Iterative Postorder Traversal Using Two Stacks179
857Least Number of Unique Integers after K Removals Leetcode Solution179
858Iterative Preorder Traversal179
859Valid Parentheses Leetcode Solution179
860Check if an Array is Stack Sortable179
861Distinct adjacent elements in an array179
862Make Two Arrays Equal by Reversing Sub-arrays Leetcode Solution179
863Check if a given array can represent Preorder Traversal of Binary Search Tree179
864Remove Duplicates from Sorted List LeetCode Solution179
865Minimum Sum Path in a Triangle179
866Number Complement Leetcode Solution179
867Find the Only Repetitive Element Between 1 to N-1179
868Daily Temperatures Leetcode Solution179
869Range LCM Queries178
870Can Place Flowers LeetCode Solution178
871Alien Dictionary LeetCode Solution178
872Matrix Chain Multiplication178
873Median of Two Sorted Arrays178
874Maximum Score After Splitting a String Leetcode Solution178
875Spiral Matrix II Leetcode Solution178
876Sort Colors178
877Minimum number of jumps to reach end178
878Sum of nearest smaller and greater number178
879Guess Number Higher or Lower LeetCode Solution178
880Minimum swaps to make sequences increasing177
881Convert BST to Min Heap177
882Count Distinct Elements in Every Window of Size K177
883Union and Intersection of two Linked Lists177
884Dividing Array into Pairs With Sum Divisible by K177
885Get Maximum in Generated Array Leetcode Solution177
886Friends Pairing Problem177
887An Interesting Method to generate Binary Numbers from 1 to n177
888Find distance between two nodes of a Binary Tree177
889Partition List Leetcode Solution177
890Diagonal Traverse LeetCode Solution177
891Maximum size subarray sum equals k177
892Find all triplets with zero sum177
893Count Negative Numbers in a Sorted Matrix LeetCode Solution177
894Infix to Postfix176
895Minesweeper LeetCode Solution176
896Water Bottles Leetcode Solution176
897Rearrange Array such that arr[i] >= arr[j] if i is even and arr[i] <= arr[j] if i is odd and j < i176
898Count Submatrices With All Ones LeetCode Solution176
899Level order Traversal in Spiral Form176
900Diagonal Traversal LeetCode Solution176
901Design a Stack With Increment Operation Leetcode Solution176
902GCDs of given index ranges in an array176
903Best Time to Buy and Sell Stock with Transaction Fee Leetcode Solution176
904A program to check if a binary tree is BST or not176
905Subset with sum divisible by m176
906Sorted Array to Balanced BST176
907Find the subarray with least average176
908Sequences of given length where every element is more than or equal to twice of previous176
909Check whether a given Binary Tree is Complete or not176
910Count ways to reach the nth stair using step 1, 2 or 3176
911Check if any two intervals overlap among a given set of intervals175
912Time Based Key-Value Store LeetCode Solution175
913Delete And Earn175
914Binary array after M range toggle operations175
915Pattern Occurrences using Stack175
916Insert into a Binary Search Tree Leetcode Solution175
917Number of Distinct Islands Leetcode Solution175
918Three way partitioning of an array around a given range174
919Destination City Leetcode Solution174
920Range sum queries without updates174
921Binary Tree Longest Consecutive Sequence LeetCode Solution174
922Convert Sorted List to Binary Search Tree174
923Construct the Rectangle Leetcode Solution174
924Guess Number Higher or Lower II174
925All Unique Triplets that Sum up to a Given Value174
926Averages of Levels in Binary Tree174
927Number of Equivalent Domino Pairs Leetcode Solution173
928Check if the given array can represent Level Order Traversal of Binary Search Tree173
929Queue using Stacks173
930Rearrange Spaces Between Words Leetcode Solution173
931Longest Palindromic Subsequence173
932Shortest Word Distance Leetcode Solution173
933K’th Largest Element in BST when modification to BST is not allowed173
934Rearrange an Array Such that arr[i] is equal to i173
935Product of Array Except Self LeetCode Solution173
936Set Matrix Zeroes Leetcode Solution173
937Trim a Binary Search Tree173
938Robot Bounded In Circle LeetCode Solution173
939Lexicographical Numbers Leetcode Solution173
940Queries for GCD of all numbers of an array except elements in a given range172
941Special Positions in a Binary Matrix Leetcode Solution172
942Analyze User Website Visit Pattern LeetCode Solution172
943Alien Dictionary172
944Construct Complete Binary Tree from its Linked List Representation172
945Difference Array | Range update query in O(1)172
946Find Common Characters Leetcode Solution172
947Print Fibonacci sequence using 2 variables172
948Palindrome Partitioning Leetcode Solution172
9494Sum171
950Maximum Frequency Stack Leetcode Solution171
951BFS for Disconnected Graph171
952Intersection of Two Linked Lists LeetCode Solution171
953Depth First Search (DFS) for a Graph171
954Spiral Matrix III LeetCode Solution171
9553 Sum171
956My Calendar I LeetCode Solution171
957Count Subarrays with Same Even and Odd Elements171
958Remove Duplicates from Sorted List II LeetCode Solution170
959Merge Two Sorted Lists Leetcode170
960Climbing stairs170
961Three Consecutive Odds Leetcode Solution170
962Maximize Sum of Array after K Negations Leetcode Solution170
963Symmetric Tree170
964Create Maximum Number170
965Minimum Height Trees LeetCode Solution170
966Vertical sum in a given binary tree170
967Construct BST from its given Level Order Traversal170
968Count Primes in Ranges169
969Word Break169
970Count subarrays where second highest lie before highest169
971Strongly Connected Component169
972Largest area rectangular sub-matrix with equal number of 1’s and 0’s169
973Unique Paths II169
974Merging Intervals169
975Count pair with Given Sum169
976Sign of the Product of an Array LeetCode Solution169
977Breadth First Search (BFS) for a Graph169
978Longest subsequence such that difference between adjacents is one168
979Longest Nice Substring LeetCode Solution168
980Reverse Nodes in K-Group168
981Stone Game II Leetcode168
982Find Maximum of Minimum for Every Window Size in a Given Array168
983Combination Sum IV LeetCode Solution168
984K maximum sums of overlapping contiguous sub-arrays168
985Kth Smallest Element in a BST Leetcode Solution168
986Maximum length subsequence with difference between adjacent elements as either 0 or 1168
987Maximum Subarray Sum Excluding Certain Elements168
988Largest Number Leetcode Solution168
989Design Hit Counter LeetCode Solution168
990Maximum Product Subarray167
991Asteroid Collision LeetCode Solution167
992Largest Substring Between Two Equal Characters Leetcode Solution167
993Next Permutation Leetcode Solution167
994Count pairs from two sorted arrays whose sum is equal to a given value x167
995Serialize and Deserialize Binary Tree167
996Number of palindromic paths in a matrix167
997Valid Boomerang Leetcode Solution167
998Length of Longest Fibonacci Subsequence166
999K Closest Points to Origin Leetcode Solution166
1000Check If a Word Occurs As a Prefix of Any Word in a Sentence Leetcode Solution166
1001Height of a generic tree from parent array166
1002Find number of pairs in an array such that their XOR is 0166
1003Print Next Greater Number of Q queries166
1004Can Make Arithmetic Progression From Sequence Leetcode Solution166
1005Scramble String LeetCode Solution166
1006Maximum Length of Repeated Subarray166
1007Shuffle 2n integers as a1-b1-a2-b2-a3-b3-..bn without using extra space166
1008Graph Valid Tree LeetCode Solution166
1009Maximum Product of Indexes of Next Greater on Left and Right166
1010String Matching in an Array Leetcode Solution166
1011Segment Tree166
1012Maximum difference between frequency of two elements such that element having greater frequency is also greater166
1013Kth Smallest Element in a Sorted Matrix LeetCode Solution165
1014Friends Of Appropriate Ages LeetCode Solution165
1015Palindrome Partitioning165
1016Find postorder traversal of BST from preorder traversal165
1017Binary Search Tree Delete Operation165
1018Generate Parentheses Leetcode Solution165
1019Find the First Circular Tour that visits all the Petrol Pumps165
1020The Painter’s Partition Problem165
1021Balanced Binary Tree165
1022Remove Duplicates from Sorted Array II Leetcode Solution165
1023Collect maximum points in a grid using two traversals165
1024Shortest Completing Word Leetcode Solution165
1025Find the Difference Leetcode Solution165
1026The Maze III LeetCode Solution165
1027Find a Peak Element II LeetCode Solution164
1028Find Duplicate Subtrees164
1029Build an Array With Stack Operations Leetcode Solution164
1030Boundary Traversal of binary tree164
1031Validate Binary Search Tree164
1032Number Of Longest Increasing Subsequence164
1033Rearrange array such that even positioned are greater than odd164
1034Minimum Index Sum of Two Lists164
1035Consecutive Characters LeetCode Solution164
1036Maximum Number of Ways to Partition an Array LeetCode Solution164
1037Largest divisible pairs subset164
1038Level Order Traversal of Binary Tree164
1039Decrypt String from Alphabet to Integer Mapping Leetcode Solution164
1040Newman-Conway Sequence164
1041Binary Search Tree164
1042Rearrange an array such that ‘arr[j]’ becomes ‘i’ if ‘arr[i]’ is ‘j’163
1043Merge Sort163
1044Move all negative elements to end in order with extra space allowed163
1045Invalid Transactions LeetCode Solution163
1046Path Sum II LeetCode Solution163
1047Construct Binary Tree from given Parent Array representation163
1048Advantages of BST over Hash Table163
1049Boolean Parenthesization Problem163
1050Kill Process LeetCode Solution163
1051Double the first element and move zero to end163
1052Maximum subsequence sum such that no three are consecutive162
1053Bitwise AND of Numbers Range LeetCode Solution162
1054Iterative Depth First Traversal of Graph162
1055Available Captures for Rook Leetcode Solution162
1056Compute nCr % p162
1057Construction of Longest Increasing Subsequence (N log N)162
1058Maximum Sum of 3 Non-Overlapping Subarrays162
1059Insertion in a Binary Tree162
1060Find Three Element From Different Three Arrays Such That a + b + c = sum161
1061Next Greater Element III LeetCode Solution161
1062Custom Sort String Leetcode Solution161
1063Determine Whether Matrix Can Be Obtained By Rotation LeetCode Solution161
1064Count minimum steps to get the given desired array161
1065First missing positive161
1066Make The String Great Leetcode Solution161
1067Ugly Numbers161
1068Subarrays with K Different Integers Leetcode Solution161
1069Find Peak Element160
1070Employee Importance LeetCode Solution160
1071Add two numbers160
1072Find maximum difference between nearest left and right smaller elements160
1073Rearrange array such that even index elements are smaller and odd index elements are greater160
1074Recover Binary Search Tree Leetcode Solution160
1075Lowest Common Ancestor160
1076Super Ugly Number159
1077Regular Expression Matching Regular Expression Matching LeetCode Solution159
1078Print all triplets in sorted array that form AP159
1079Partition Equal Subset Sum159
1080Minimum Size Subarray Sum159
1081Number of Closed Islands Leetcode Solution159
1082Maximize Distance to Closest Person LeetCode Solution159
1083Defanging an IP Address LeetCode Solution159
1084Smallest Common Region Leetcode Solution159
1085Print Right View of a Binary Tree159
1086Level order traversal using two Queues159
1087Morris Inorder Traversal159
1088Find whether a subarray is in form of a mountain or not159
1089Maximum weight transformation of a given string159
1090Remove duplicates from sorted array159
1091Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution158
1092Increasing Triplet Subsequence LeetCode Solution158
1093Implement Trie (Prefix Tree) Leetcode Solution158
1094Kth Smallest Product of Two Sorted Arrays LeetCode Solution158
1095Number of siblings of a given Node in n-ary Tree158
1096Valid Tic-Tac-Toe State LeetCode Solution158
1097Largest BST Subtree LeetCode Solution158
1098Remove Palindromic Subsequences Leetcode Solution158
1099Ugly Number II LeetCode Solution157
1100Palindromic Substrings Leetcode Solution157
1101Binary Tree Right Side View LeetCode Solution157
1102Serialize and Deserialize Binary Tree LeetCode Solution157
1103Binary Tree Data Structure157
1104Palindrome Permutation LeetCode Solution157
1105Cells with Odd Values in a Matrix LeetCode Solution157
1106Find the minimum distance between two numbers157
1107Populating Next Right Pointers in Each Node Leetcode Solution156
1108Longest Bitonic Subsequence156
1109Products of ranges in an array156
1110Number of Students Doing Homework at a Given Time Leetcode Solution156
1111Reformat The String Leetcode Solution156
1112Bus Routes Leetcode Solution156
1113Search in Sorted Rotated Array156
1114Count Largest Group Leetcode Solution156
1115Path Sum156
1116Day of the Year Leetcode Solution156
1117Maximum Depth Of Binary Tree155
1118Find Smallest Range Containing Elements from k Lists155
1119Root to Leaf path with target sum Leetcode Solutions155
1120Divisible Pairs Counting155
1121Sum of Even Numbers After Queries155
1122Distinct Subsequences155
1123Search Insert Position155
1124Find Two Non-overlapping Sub-arrays Each With Target Sum LeetCode Solution155
1125Write Code to Determine if Two Trees are Identical154
1126Bottom View of a Binary Tree154
1127Prime Palindrome LeetCode Solution154
1128Minimum Score Triangulation of Polygon Leetcode Solution154
1129Thousand Separator Leetcode Solution154
1130Iterative method to find ancestors of a given binary tree154
1131Clone a Binary Tree with Random Pointers154
1132Minimum Absolute Difference in BST Leetcode Solution153
1133Queries for Number of Distinct Elements in a Subarray153
1134Mean of Array After Removing Some Elements Leetcode Solution153
1135Third Maximum Number Leetcode Solution153
1136Longest Repeated Subsequence153
1137Moser-de Bruijn Sequence153
1138Longest Increasing Consecutive Subsequence153
1139Construct K Palindrome Strings LeetCode Solution152
1140Golomb sequence152
1141Reformat Date LeetCode Solution152
1142Minimum sum of squares of character counts in a given string after removing k characters152
1143Level of Each node in a Tree from source node152
1144Longest Subarray of 1’s After Deleting One Element LeetCode Solution152
1145Maximum Product of Splitted Binary Tree LeetCode Solution152
1146Print modified array after executing the commands of addition and subtraction152
1147Closest Binary Search Tree Value Leetcode Solution152
1148Find a sorted subsequence of size 3 in linear time152
1149Diameter of N-Ary Tree LeetCode Solution152
1150Minimum Swaps To Make Sequences Increasing LeetCode Solution152
1151Replace two consecutive equal values with one greater151
1152Maximize sum of consecutive differences in a circular array151
1153Cutting a Rod151
1154Find Largest Value in Each Tree Row LeetCode Solution151
1155Rotate Array151
1156Constant time range add operation on an array151
1157Closest Leaf in a Binary Tree LeetCode Solution151
1158Maximum Product Subarray151
1159Search an Element in Sorted Rotated Array151
1160Minimum Moves to Equal Array Elements LeetCode Solution151
1161Priority Queue151
1162Count even length binary sequences with same sum of first and second half bits151
1163Swap Nodes In Pairs151
1164Delete Nodes and Return Forest Leetcode Solution150
1165Topological Sorting150
1166Minimum Cost to Move Chips to The Same Position LeetCode Solution150
1167Contiguous Array LeetCode Solution150
1168Compare Strings by Frequency of the Smallest Character Leetcode Solution150
1169Find maximum length Snake sequence150
1170Kth Smallest Number in Multiplication Table Leetcode Solution150
1171Convert BST into a Min-Heap without using array150
1172Remove Max Number of Edges to Keep Graph Fully Traversable Leetcode Solution149
1173Web Crawler LeetCode Solution149
1174First Bad Version149
1175Search Suggestions System LeetCode Solution149
1176Factorial Trailing Zeroes LeetCode Solution149
1177Count Pairs Whose Products Exist in Array149
1178Decision Tree149
1179Decrease Elements To Make Array Zigzag LeetCode Solution149
1180Check Array Formation Through Concatenation Leetcode Solution149
1181Subset Sum Problem in O(sum) space149
1182Maximum number of segments of lengths a, b and c148
1183Maximum Binary Tree148
1184Possible Bipartition LeetCode Solution148
1185Merge two BSTs with limited extra space148
1186Perfect Squares LeetCode Solution148
1187Minimum Sideway Jumps LeetCode Solution148
1188Transform a BST to Greater sum Tree147
1189K’th Largest element in BST using constant extra space147
1190Valid Triangle Number147
1191Reverse a Path in BST using Queue147
1192Given a binary tree, how do you remove all the half nodes?147
1193Matchsticks to Square Leetcode Solution147
1194Binary Tree to Binary Search Tree Conversion147
1195Convert Sorted Array to Binary Search Tree LeetCode Solutions146
1196Concatenation of Array LeetCode Solution146
1197Sliding Window Median Leetcode Solution146
1198Red-Black Tree Introduction146
1199Divide Two Integers Leetcode Solution146
1200Sum of Left Leaves LeetCode Solution146
1201Path Crossing Leetcode Solution146
1202Maximum sum of a path in a Right Number Triangle146
1203Number of Orders in the Backlog Leetcode Solution146
1204Maximum Value at a Given Index in a Bounded Array LeetCode Solution146
1205Swapping Nodes in a Linked List Leetcode Solution145
1206Queries on Probability of Even or Odd Number in given Ranges145
1207Maximum sum bitonic subarray145
1208Maximum sum of pairs with specific difference145
1209Champagne Tower LeetCode Solution144
1210Find the smallest binary digit multiple of given number144
1211Integer Break LeetCode Solution144
1212Valid Perfect Square LeetCode Solution144
1213New 21 Game144
1214Queue Reconstruction by Height144
1215How to print maximum number of A’s using given four keys144
1216Convert Integer to the Sum of Two No-Zero Integers Leetcode Solution144
1217Find minimum number of merge operations to make an array palindrome144
1218Lowest Common Ancestor of a Binary Tree Leetcode Solution144
1219Range Queries for Longest Correct Bracket Subsequence143
1220Maximum Array from Two given Arrays Keeping Order Same143
1221Print n terms of Newman-Conway Sequence143
1222Maximum Sum Increasing Subsequence142
1223Flatten 2D Vector LeetCode Solution142
1224Guess The Word142
1225Moving Stones Until Consecutive Leetcode Solution142
1226Graph and its representation142
1227Lowest Common Ancestor in Binary Search Tree142
1228The kth Factor of n Leetcode Solution142
1229LRU Cache Leetcode Solution142
1230Check if all levels of two Binary Tree are anagrams or not142
1231Find Minimum in Rotated Sorted Array II LeetCode Solution142
1232Array Queries for multiply replacements and product142
1233Range Sum Query using Sparse Table142
1234Maximize Elements Using Another Array141
1235Bold Words in String LeetCode Solution141
1236Kth Smallest Element in a BST141
1237Longest Common Prefix Using Word by Word Matching141
1238Largest Plus Sign Leetcode Solution140
1239Merge k Sorted Lists Leetcode Solution140
1240Mean of range in array140
1241Print modified array after multiple array range increment operations140
1242Contiguous Array140
1243Write a function to get the intersection point of two Linked Lists140
1244Arithmetic Slices II – Subsequence LeetCode Solution140
1245BST to a Tree with Sum of all Smaller Keys139
1246Maximum Product Subarray139
1247Filter Restaurants by Vegan-Friendly, Price and Distance Leetcode Solution139
1248Count Subsets Having Distinct Even Numbers139
1249Graph Cloning139
1250Minimum Remove to Make Valid Parentheses LeetCode Solution138
1251Find k-th smallest element in BST (Order Statistics in BST)138
1252Missing Number138
1253Design Skiplist LeetCode Solution138
1254Different Ways to Add Parentheses Leetcode Solution137
1255Check for Identical BSTs without building the trees137
1256Parallel Courses II LeetCode Solution137
1257Power of Two137
1258Check if each internal node of a BST has exactly one child136
1259Min Cost Climbing Stairs LeetCode Solution136
1260Image Overlap LeetCode Solution136
1261Minimum Time to Collect All Apples in a Tree LeetCode Solution136
1262Symmetric Tree LeetCode Solution Leetcode Solution136
1263Check Completeness of a Binary Tree LeetCode Solution135
1264Verify Preorder Serialization of a Binary Tree135
1265Check in binary array the number represented by a subarray is odd or even135
1266Next greater element135
1267Check if two nodes are on the same path in a Tree135
1268Koko Eating Bananas LeetCode Solution134
1269Smallest Range II Leetcode Solution134
1270Print Ancestors of a Given Binary Tree Node Without Recursion134
1271Excel Sheet Column Title LeetCode Solution134
1272Count and Toggle Queries on a Binary Array133
1273Orderly Queue LeetCode Solution133
1274Longest Substring Without Repeating Characters Leetcode Solution133
1275Palindrome Number LeetCode Solution133
1276Vertical Order Traversal of Binary Tree LeetCode Solution132
1277Merge Sorted Array132
1278Number of elements less than or equal to a given number in a given subarray131
1279Arranging Coins Leetcode Solution131
1280Array Nesting Leetcode Solution131
1281Largest Submatrix With Rearrangements LeetCode Solution131
1282Check if X can give change to every person in the Queue131
1283Check If a String Can Break Another String Leetcode Solution130
1284Palindrome Partitioning129
1285Peeking Iterator LeetCode Solution129
1286Continuous Subarray Sum LeetCode Solution129
1287Find maximum average subarray of k length128
1288Find the Winner of the Circular Game LeetCode Solution128
1289Add Two Numbers II Leetcode Solution128
1290Queries for Decimal Values of Subarrays of a Binary Array128
1291Maximum product of an increasing subsequence127
1292Range Minimum Query (Square Root Decomposition and Sparse Table)126
1293Insert Delete GetRandom O(1) Leetcode Solution126
1294Newman–Shanks–Williams prime126
1295Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution125
1296Encoded String With Shortest Length LeetCode Solution124
1297Number of indexes with equal elements in given range123
1298Convert to Base -2 LeetCode Solution123
1299Reach a Number LeetCode Solution123
1300Check given array of size n can represent BST of n levels or not123
1301Jump Game IV LeetCode Solution123
1302Random Pick Index LeetCode Solution122
1303Minimum Number of People to Teach LeetCode Solution121
1304Minimum Possible Integer After at Most K Adjacent Swaps On Digits LeetCode Solution121
1305Binary Tree to Binary Search Tree Conversion using STL set121
1306Convert a BST to a Binary Tree such that sum of all greater keys is added to every key120
1307Minimum Total Space Wasted With K Resizing Operations LeetCode Solution119
1308Design A Leaderboard Leetcode Solution119
1309Design Underground System Leetcode Solution118
1310Queries on XOR of greatest odd divisor of the range118
1311Shifting Letters LeetCode Solution117
1312Print Maximum Length Chain of Pairs116
1313Detect Capital Leetcode Solution113
1314Minimum Swaps to Group All 1’s Together Leetcode Solution113
1315Minimum Path Sum Leetcode Solution111
1316Count Sub Islands LeetCode Solution110
1317Top K Frequent Elements LeetCode Solution110
1318Substring with Concatenation of All Words Leetcode Solution109
1319Odd Even Linked List Leetcode Solution108
1320Monotonic Array Leetcode Solution107
1321Binary Tree Inorder Traversal LeetCode Solution105
1322Maximum Population Year LeetCode Solution105
1323Decode String Leetcode Solution105
1324Find the Town Judge LeetCode Solution104
1325Longest Common Subsequence LeetCode Solution104
1326Shortest Unsorted Continuous Subarray LeetCode Solution99
1327Rectangle Overlap LeetCode Solution97
1328Sum Root to Leaf Numbers LeetCode Solution96
1329Best Meeting Point LeetCode Solution96
1330Find the Town Judge LeetCode Solution95
1331Maximum Population Year LeetCode Solution94
1332Insert into a Sorted Circular Linked List LeetCode Solution94
1333Flatten Binary Tree to Linked List LeetCode Solution94
1334Design Add and Search Words Data Structure LeetCode Solution93
1335Score of Parenthesis LeetCode Solution92
1336Reveal Cards In Increasing Order Leetcode Solution91
1337Stone Game IV LeetCode Solution91
1338Valid Triangle Number LeetCode Solution90
1339Is Graph Bipartite? LeetCode Solution90
1340Range Sum Query 2D – Immutable LeetCode Solution90
1341Divide Chocolate LeetCode Solution84
1342Step-By-Step Directions From a Binary Tree Node to Another LeetCode Solution76
1343Range Sum of BST LeetCode Solution71
1344Reverse Integer Leetcode Solution71
1345Rotate String LeetCode Solution69
1346Find K Closest Elements LeetCode Solution67
1347Sort Colors LeetCode Solution65
1348Maximum Side Length of a Square with Sum Less than or Equal to Threshold LeetCode Solution64
1349Excel Sheet Column Number LeetCode Solution61
1350Maximum Size Subarray Sum Equals k Leetcode Solution55
1351Valid Anagram Leetcode Solution47
1352Camelcase Matching Leetcode Solution47
1353H-Index Leetcode Solution47
1354Most Stones Removed with Same Row or Column LeetCode Solution46
1355Sliding Window Maximum LeetCode Solution46
1356Container With Most Water LeetCode Solution45
1357Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution44
1358Next Permutation LeetCode Solution44
1359Group Anagrams LeetCode Solution44
1360Binary Search LeetCode Solution43
1361High Five LeetCode Solution43
1362Find Peak Element LeetCode Solution43
1363Paint House LeetCode Solution42
1364Group Shifted Strings Leetcode Solution40
1365Flatten Binary Tree to Linked List LeetCode Solution39
1366The Number of Weak Characters in the Game LeetCode Solution38
1367Next Greater Element I Leetcode Solution38
1368Minimum Number of Arrows to Burst Balloons LeetCode Solution38
1369Sentence Screen Fitting LeetCode Solution38
1370Split Linked List in Parts Leetcode Solution38
1371Isomorphic Strings LeetCode Solution37
1372Valid Triangle Number LeetCode Solution36
1373Unique Binary Search Trees LeetCode Solution36
1374Count Good Nodes in Binary Tree LeetCode Solution35
1375Peak Index in a Mountain Array LeetCode Solution34
1376Insert Delete GetRandom O(1) – Duplicates allowed LeetCode Solution34
1377Break a Palindrome LeetCode Solution34
1378Closest Binary Search Tree Value II LeetCode Solution33
1379All Possible Full Binary Trees LeetCode Solution33
1380Minimum Increment to Make Array Unique Leetcode Solution33
1381Best Time to Buy and Sell Stock IV LeetCode Solution33
1382Swim in Rising Water LeetCode Solution33
1383Max Sum of Two Non-Overlapping Subarrays LeetCode Solution32
1384Single Element in a Sorted Array LeetCode Solution32
1385Implement Rand10() Using Rand7() Leetcode Solution31
1386Remove All Ones With Row and Column Flips Leetcode Solution31
1387Contains Duplicate LeetCode Solution31
1388Trapping Rain Water II LeetCode Solution30
1389Validate Stack Sequences LeetCode Solution30
1390Find First and Last Position of Element in Sorted Array LeetCode Solution30
1391Lowest Common Ancestor of a Binary Search Tree Leetcode Solution30
1392Greatest Sum Divisible by Three LeetCode Solution28
1393Reverse Nodes in k-Group LeetCode Solution28
1394Implement strStr() LeetCode Solution27
1395Detect Squares LeetCode Solution27
1396Stone Game IV LeetCode Solution26
1397Fibonacci Number LeetCode Solution24
1398Invert Binary Tree LeetCode Solution24
1399Design Bounded Blocking Queue LeetCode Solution23
1400Total Hamming Distance LeetCode Solution23
1401Minimum Number of Operations to Move All Balls to Each Box LeetCode Solution22
1402Unique Paths III LeetCode Solution20
1403Candy LeetCode Solution18
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