Monotonic Array Leetcode Solution

Difficulty Level Easy
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Problem Statement:

The Monotonic Array Leetcode Solution – Given an array is monotonic if it is either monotone increasing or monotone decreasing. An array nums is monotone increasing if for all i <= jnums[i] <= nums[j]. An array nums is monotone decreasing if for all i <= jnums[i] >= nums[j].

Given an integer array nums, return true if the given array is monotonic, or false otherwise.


Example 1:

nums = [1,2,2,3]
Output: true


[1, 2, 2, 3] – this array is monotone increasing as 1<2<=2<3 

Example 2:

nums = [1,3,2]
Output: false


[1, 3, 2] – this array is neither monotone increasing nor monotone decreasing as 1>3<2. Both increasing and decreasing sequences are present in the array.


An array is monotonic if it is monotone increasing, or monotone decreasing. Since a <= b and b <= c implies a <= c, we only need to check adjacent elements to determine if the array is monotone increasing (or decreasing, respectively). We can check each of these properties in one pass.


Monotonic Array Leetcode SolutionPin

  1. Initialize two variables increase and decrease with 0.
  2. Traverse the given array, compare the pair elements of the array and check if the current element in the array is greater than or less than the next element.
  3. If the current element is greater, then mark the “increase” variable as 1, and if the current element is less than the next element then mark the “decrease” variable as 1.
  4. If in any iteration both the increase and decrease variable become equal to 1 then we return false.
  5. Otherwise, we return true after the loop ends as it is proved that the given array is monotonic.


C++ Program of  Monotonic Array Leetcode Solution:

class Solution {
    bool isMonotonic(vector<int>& nums) {
        int increase=0, decrease=0;
        int n=nums.size();
        for(int i=0;i<n-1;i++){
            if(nums[i] > nums[i+1]) increase = 1;
            if(nums[i] < nums[i+1]) decrease = 1;
            if(increase == 1 && decrease == 1) return false;
        return true;

Java Program of  Monotonic Array Leetcode Solution:

class Solution {
    public boolean isMonotonic(int[] nums) {
        int increase=0, decrease=0;
        int n=nums.length;
        for(int i=0;i<n-1;i++){
            if(nums[i] > nums[i+1]) increase = 1;
            if(nums[i] < nums[i+1]) decrease = 1;
            if(increase == 1 && decrease == 1) return false;
        return true;

Complexity Analysis for Monotonic Array Leetcode Solution:

Time Complexity:

The Time Complexity of the code is O(N) as we traverse through the given array only once.

Space Complexity:

The Space Complexity of the code is O(1) because we don’t need any extra space to solve this problem.

A similar type of question to practice:

Check if the Elements of an Array are Consecutive


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590Maximum path sum in a triangle173
591Distance Between Bus Stops Leetcode Solution173
592Trapping Rain Water LeetCode Solution173
5933Sum Closest LeetCode Solution173
594Shortest Path in a Grid with Obstacles Elimination LeetCode Solution173
595Maximum Number of Chocolates to be Distributed Equally Among k Students173
596Find the smallest positive integer value that cannot be represented as sum of any subset of a given array173
597Minimum number of distinct elements after removing m items172
598Maximum Distance in Array172
599Minimum insertions to form a palindrome with permutations allowed171
600Stone Game LeetCode171
601Same Tree LeetCode Solution171
602Rotate Image LeetCode Solution171
603Sort Characters By Frequency LeetCode Solution171
604Minimum number of subsets with distinct elements171
605How to check if two given sets are disjoint?171
606Find minimum difference between any two elements171
607Remove All Occurrences of a Substring LeetCode Solution170
608XOR Operation in an Array Leetcode Solution170
609Word Wrap Problem170
610Painting Fence Algorithm170
611Sieve of Eratosthenes170
612Permutation in String Leetcode Solution170
613Bubble sort using two Stacks170
614Frog Jump Leetcode Solution170
615Word Pattern170
616Sort Array By Parity LeetCode Solution170
617Find if an Expression has Duplicate Parenthesis or Not170
618K Empty Slots LeetCode170
619Tracking current Maximum Element in a Stack169
620Applications of Breadth First Search and Depth First Search169
621Printing brackets in Matrix Chain Multiplication Problem169
622Smallest Good Base169
623Best Time to Buy and Sell Stock LeetCode Solution169
624Isomorphic Strings169
625House Robber169
626Defanging an IP Address Leetcode Solution169
627Replace Elements with Greatest Element on Right Side Leetcode Solution169
628Distance of nearest cell having 1 in a binary matrix169
629Minimum Depth of Binary Tree Leetcode Solution169
630Reverse a stack without using extra space in O(n)169
631Maximum Consecutive Numbers Present in an Array168
632Longest Substring with At Most K Distinct Characters LeetCode Solution168
633Segregate 0s and 1s in an Array168
634Minimum Cost to Hire K Workers168
635Longest Increasing Subsequence168
636License Key Formatting Leetcode Solution168
637Find the Duplicate Number LeetCode Solution168
638Find Sum of all unique sub-array sum for a given array168
639Optimal Account Balancing LeetCode Solution167
640Moving Average from Data Stream Leetcode Solution167
641Valid Palindrome II Leetcode Solution167
642Non-overlapping sum of two sets167
643Binary Tree Zigzag Level Order Traversal LeetCode Solution167
644Iterative Method to find Height of Binary Tree167
645Find Maximum Level sum in Binary Tree167
646Coin Change Problem167
647Wiggle Sort167
648Maximum difference between first and last indexes of an element in array167
649Count Good Nodes in Binary Tree Leetcode Solution167
650Maximum Number of Occurrences of a Substring Leetcode Solution166
651Kth Missing Positive Number Leetcode Solution166
652Merge Two Balanced Binary Search Trees166
653Sum of All Odd Length Subarrays Leetcode Solution166
654How to Create Mergable Stack?166
655Check If It Is a Straight Line Leetcode Solution166
656GCD Of Two Numbers166
657Employee Free Time LeetCode Solution166
658Queries for counts of array elements with values in given range166
659Best Time to Buy and Sell Stock with Cooldown Leetcode Solution166
660Minimum Number of Steps to Make Two Strings Anagram Leetcode Solutions166
661Convert an array to reduced form165
662Longest Substring with At Least K Repeating Characters LeetCode Solution165
663Letter Combinations of a Phone Number165
664Path With Maximum Minimum Value LeetCode Solution165
665Strobogrammatic Number LeetCode Solution165
666Find the Distance Value Between Two Arrays Leetcode Solution165
667Valid Palindrome165
668Find Largest d in Array such that a + b + c = d165
669Flipping an Image LeetCode Solution165
670Find pairs with given sum such that elements of pair are in different rows164
671Delete consecutive same words in a sequence164
672Reorganize String164
673Number of Provinces Leetcode Solution164
674Maximum Number of Coins You Can Get Leetcode Solution164
675Partition Labels LeetCode Solution164
676Number of Dice Rolls With Target Sum LeetCode Solution163
677Populating Next Right Pointers in Each Node163
678Edit Distance LeetCode Solution163
679Longest Increasing Path in a Matrix LeetCode Solution163
680Recover Binary Search Tree163
681Print the Fibonacci numbers in reverse order163
682Permutation Sequence LeetCode Solution163
683Valid Perfect Square Leetcode Solution163
684Inorder Successor of a node in Binary Tree163
685Power of Four Leetcode Solution163
686K Empty Slots163
687Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest163
688Reducing Dishes LeetCode Solution163
689Check If Two String Arrays are Equivalent Leetcode Solution163
690Increasing Decreasing String Leetcode Solution162
691Factorial Trailing Zeroes Leetcode Solution162
692Lucky Numbers in a Matrix Leetcode Solution162
693Check if a queue can be sorted into another queue using a stack162
694Dynamic Programming Basics162
695Partition Array Into Three Parts With Equal Sum Leetcode Solution162
696Remove Invalid Parentheses Leetcode Solution162
697Sort Array by Increasing Frequency Leetcode Solution162
698Form minimum number from given sequence162
699Construct BST from given Preorder Traversal162
700BFS vs DFS for Binary Tree162
701String to Integer (atoi) LeetCode Solution162
702Merge Two Binary Trees LeetCode Solution162
703To Lower Case Leetcode Solution161
704Binary Tree zigzag level order Traversal161
705Convert a Number to Hexadecimal Leetcode Solution161
706Maximum Product of Two Elements in an Array Leetcode Solution161
707Unique Paths II Leetcode Solution161
708Ugly Number Leetcode Solution161
709Reservoir Sampling161
710Reversing a Queue using Recursion161
711Find whether an array is subset of another array161
712Subset Sum Leetcode161
713Robot Room Cleaner Leetcode Solution161
714Reverse Only Letters LeetCode Solution160
715Find the Smallest Divisor given a Threshold Leetcode Solution160
716Find Leaves of Binary Tree LeetCode Solution160
717Delete Nth node from the end of the given linked list160
718Keyboard Row Leetcode Solution160
719Binomial Coefficient160
720Majority Element II Leetcode Solution160
721Restore IP Addresses Leetcode Solution160
722Perform String Shifts Leetcode159
723Check if Two Expressions With Brackets are Same159
724Add and Search Word – Data structure design LeetCode159
725Find the largest multiple of 3159
726Decompress Run-Length Encoded List Leetcode Solution159
727Bulb Switcher LeetCode Solution159
728Numbers with prime frequencies greater than or equal to k159
729Finding K closest element158
730Maximum Product of Three Numbers LeetCode Solution158
731Maximum 69 Number Leetcode Solution158
732Find Pair with Greatest Product in Array158
733Minimum Cost For Tickets Leetcode Solution158
734Number of Islands II LeetCode Solution158
735Morris Traversal158
736Sum of f(a[i], a[j]) over all pairs in an array of n integers158
737Find the node with minimum value in a Binary Search Tree158
738Hamming Distance Leetcode Solution158
739Tiling Problem157
740Maximum Depth of N-ary Tree Leetcode Solution157
741Find Maximum Depth of Nested Parenthesis in a String157
742Minimum Distance Between BST Nodes Leetcode Solution157
743String Compression LeetCode Solution157
744Student Attendance Record I Leetcode Solution157
745First Unique Character in a String LeetCode Solution157
746Sorted Linked List to Balanced BST157
747Generate all possible sorted arrays from alternate elements of two given sorted arrays157
748Diagonal Traversal of Binary Tree157
749Invert Binary Tree LeetCode Solution157
750Word Pattern LeetCode Solution157
751Merge K Sorted Linked Lists157
752Find unique character in a string156
753Binary Tree Maximum Path Sum LeetCode Solution156
754Special Array With X Elements Greater Than or Equal X Leetcode Solution156
755Longest Span with same Sum in two Binary arrays156
756Minimum Height Trees156
757Rank Transform of an Array Leetcode Solution156
758Find All Duplicates in an Array LeetCode Solution156
759Non-decreasing Array LeetCode Solution156
760Check If Array Pairs Are Divisible by k LeetCode Solution156
761Queue based approach for first non-repeating character in a stream156
762Best Meeting Point LeetCode Solution156
763Kth ancestor of a node in binary tree156
764Largest subarray with equal number of 0s and 1s156
765Minimum time required to rot all oranges156
766Symmetric Tree Leetcode Solution156
767Final Prices With a Special Discount in a Shop Leetcode Solution155
768Evaluate Reverse Polish Notation LeetCode Solution155
769Race Car LeetCode Solution155
770Largest Rectangle in Histogram LeetCode Solution155
771Maximum Length of a Concatenated String with Unique Characters Leetcode Solution155
772Search a 2D Matrix II Leetcode Solution155
773Find Median from Data Stream LeetCode Solution155
774Jump Game155
775Find if Path Exists in Graph Leetcode Solution155
776Elements to be added so that all elements of a range are present in array155
777Remove brackets from an algebraic string containing + and – operators155
778Minimize Maximum Pair Sum in Array LeetCode Solution155
779Largest rectangular sub-matrix whose sum is 0155
780Stack Permutations (Check if an array is stack permutation of other)155
781Snakes and Ladders LeetCode Solution154
782Count items common to both the lists but with different prices154
783k-th missing element in increasing sequence which is not present in a given sequence154
784Remove Nth Node From End of List Leetcode Solution154
785Linked List Cycle154
786Split a String in Balanced Strings Leetcode Solution154
787Maximum Difference Between Increasing Elements LeetCode Solution154
788Partition to K Equal Sum Subsets Leetcode Solution154
789Valid Number154
790Program for Bridge and Torch problem154
791Transpose Graph154
792Sort an array according to the order defined by another array153
793Search in a Binary Search Tree Leetcode Solution153
794Deletion in a Binary Tree153
795N-Queens LeetCode Solution153
796Last Stone Weight II LeetCode Solution153
797Print a Binary Tree in Vertical Order153
798Count quadruples from four sorted arrays whose sum is equal to a given value x153
799Minimum Jumps to Reach Home LeetCode Solution153
800Growable array based stack153
801Get Maximum in Generated Array Leetcode Solution153
802Nearest Exit from Entrance in Maze LeetCode Solution153
803Number of NGEs to the Right153
804Maximum Profit in Job Scheduling Leetcode Solution152
805Minimum number of jumps to reach end152
806Crawler Log Folder Leetcode Solution152
807A Space Optimized DP solution for 0-1 Knapsack Problem152
808Merge Sorted Array LeetCode Solution152
809Iterative Preorder Traversal152
810Remove Duplicates from Sorted List LeetCode Solution152
811Interval Tree152
812Minimum swaps to make sequences increasing152
813Reorder Data in Log Files LeetCode Solution152
814String comparison containing wildcards152
815Minimum Time Visiting All Points Leetcode Solution152
816Check for Palindrome after every character replacement Query152
817Circular Queue152
818Priority Queue using doubly linked list152
819Total Numbers With no Repeated Digits in a Range152
820Subarray Product Less Than K LeetCode Solution152
821Remove Duplicates from Sorted List II152
822Relative Ranks Leetcode Solution152
823Number Complement Leetcode Solution152
824Course Schedule II – LeetCode152
825Nested List Weight Sum II LeetCode Solution152
826Form Minimum Number From Given Sequence151
827Longest Subarray Having Count of 1s One More than Count of 0s151
828One Edit Distance LeetCode Solution151
829Spiral Matrix II Leetcode Solution151
830Base 7 Leetcode Solution151
831Sort Array By Parity II Leetcode Solution151
832Find all triplets with zero sum151
833Maximum size subarray sum equals k151
834Given an Array of Pairs Find all Symmetric Pairs in it150
835Regular Expression Matching150
836Valid Parentheses Leetcode Solution150
837Convert BST to Min Heap150
838Maximum Nesting Depth of the Parentheses Leetcode Solution150
839Brick Wall LeetCode Solution150
840Alien Dictionary LeetCode Solution150
841Make Two Arrays Equal by Reversing Sub-arrays Leetcode Solution150
842Path with maximum average value150
843Insert into a Binary Search Tree Leetcode Solution149
844Find All Possible Recipes from Given Supplies LeetCode Solution149
845Check whether a given Binary Tree is Complete or not149
846Sort Colors149
847Friends Pairing Problem149
848Can Place Flowers LeetCode Solution149
849Subsequence of Size K With the Largest Even Sum LeetCode Solution149
850Check if a given array can represent Preorder Traversal of Binary Search Tree149
851Binary Search Tree Search and Insertion149
852Find the subarray with least average149
853Clone Graph LeetCode Solution149
854Level order Traversal in Spiral Form149
855Subset with sum divisible by m149
856Partition List Leetcode Solution149
857Top K Frequent Words LeetCode Solution149
858Minimum Number of Taps to Open to Water a Garden LeetCode Solution149
859Tree Traversal (Preorder, Inorder & Postorder)148
860Find Maximum Sum Possible Equal Sum of Three Stacks148
861Design a Stack With Increment Operation Leetcode Solution148
862Guess Number Higher or Lower LeetCode Solution148
863Find the Only Repetitive Element Between 1 to N-1148
864Permutation Coefficient148
865Matrix Chain Multiplication148
866Count Distinct Elements in Every Window of Size K148
867Count Negative Numbers in a Sorted Matrix LeetCode Solution148
868Sequences of given length where every element is more than or equal to twice of previous148
869Missing Element in Sorted Array LeetCode Solution148
870Minimum Sum Path in a Triangle147
871Water Bottles Leetcode Solution147
872Repeated Substring Pattern LeetCode Solution147
873Balanced Expression with Replacement147
874Best Time to Buy and Sell Stock with Transaction Fee Leetcode Solution147
875Identify and Mark Unmatched Parenthesis in an Expression147
876Diagonal Traverse LeetCode Solution147
877Number of Days Between Two Dates LeetCode Solution147
878Design Browser History LeetCode Solution147
879Distinct adjacent elements in an array147
880Sum of nearest smaller and greater number147
881An Interesting Method to generate Binary Numbers from 1 to n147
882Range LCM Queries147
883Diagonal Traversal LeetCode Solution147
884Maximum Score After Splitting a String Leetcode Solution146
885Union and Intersection of two Linked Lists146
886Daily Temperatures Leetcode Solution146
887GCDs of given index ranges in an array146
888Check if an Array is Stack Sortable146
889Three way partitioning of an array around a given range146
890Brightest Position on Street LeetCode Solution146
891BFS for Disconnected Graph146
892Convert Sorted List to Binary Search Tree146
893Check if stack elements are pairwise consecutive146
894Time Based Key-Value Store LeetCode Solution146
895K’th Largest Element in BST when modification to BST is not allowed146
896Sorted Array to Balanced BST146
897Insert Delete GetRandom146
898Shortest Word Distance Leetcode Solution146
899LCS (Longest Common Subsequence) of three strings146
900Rearrange an Array Such that arr[i] is equal to i146
901Guess Number Higher or Lower II146
902Minimum sum of multiplications of n numbers146
903Spiral Matrix III LeetCode Solution145
904Rearrange Array such that arr[i] >= arr[j] if i is even and arr[i] <= arr[j] if i is odd and j < i145
905Find distance between two nodes of a Binary Tree145
906Check if the given array can represent Level Order Traversal of Binary Search Tree145
907Delete And Earn145
908Destination City Leetcode Solution145
909Lemonade Change Leetcode Solution145
910Least Number of Unique Integers after K Removals Leetcode Solution145
911Range sum queries without updates145
912Count ways to reach the nth stair using step 1, 2 or 3145
913Robot Bounded In Circle LeetCode Solution145
914Minimum Swaps to Make Strings Equal Leetcode Solution145
915Palindrome Partitioning Leetcode Solution144
916Find Common Characters Leetcode Solution144
917Rearrange Spaces Between Words Leetcode Solution144
918Vertical sum in a given binary tree144
919Print Fibonacci sequence using 2 variables144
920Number of Distinct Islands Leetcode Solution144
922Merge Two Sorted Lists Leetcode144
923Construct BST from its given Level Order Traversal144
924Construct the Rectangle Leetcode Solution143
925Maximum Frequency Stack Leetcode Solution143
926Alien Dictionary143
927Stone Game II Leetcode143
928Maximum Subarray Sum Excluding Certain Elements143
929Special Positions in a Binary Matrix Leetcode Solution143
930Construct Complete Binary Tree from its Linked List Representation143
931A program to check if a binary tree is BST or not143
932Split Array Into Consecutive Subsequences143
9333 Sum143
934Averages of Levels in Binary Tree143
935Minimum Height Trees LeetCode Solution143
936Longest Palindromic Subsequence142
937Check if any two intervals overlap among a given set of intervals142
938Binary Tree Longest Consecutive Sequence LeetCode Solution142
939Difference Array | Range update query in O(1)142
940Iterative Postorder Traversal Using Two Stacks142
941Strongly Connected Component142
942Infix to Postfix142
943Queries for GCD of all numbers of an array except elements in a given range142
944Trim a Binary Search Tree142
945Set Matrix Zeroes Leetcode Solution142
946Remove Duplicates from Sorted List II LeetCode Solution142
947Lexicographical Numbers Leetcode Solution142
948Queue using Stacks142
949Count Subarrays with Same Even and Odd Elements142
950Largest area rectangular sub-matrix with equal number of 1’s and 0’s142
951Unique Paths II141
952Sliding Window Maximum141
953All Unique Triplets that Sum up to a Given Value141
954Binary array after M range toggle operations141
955Analyze User Website Visit Pattern LeetCode Solution141
956Collect maximum points in a grid using two traversals141
957Find all permuted rows of a given row in a matrix141
958Number of Equivalent Domino Pairs Leetcode Solution141
959Shuffle 2n integers as without using extra space141
960Count Submatrices With All Ones LeetCode Solution141
961Sign of the Product of an Array LeetCode Solution140
962Reverse Nodes in K-Group140
963Dividing Array into Pairs With Sum Divisible by K140
964Minesweeper LeetCode Solution140
965Create Maximum Number140
966Count subarrays where second highest lie before highest140
967Word Break140
968Pattern Occurrences using Stack140
969Merging Intervals140
970Can Make Arithmetic Progression From Sequence Leetcode Solution140
971Find postorder traversal of BST from preorder traversal140
972Three Consecutive Odds Leetcode Solution140
973Intersection of Two Linked Lists LeetCode Solution140
974Palindrome Partitioning139
975Symmetric Tree139
976Count Primes in Ranges139
977Length of Longest Fibonacci Subsequence139
978The Painter’s Partition Problem139
979Median of Two Sorted Arrays139
980Product of Array Except Self LeetCode Solution139
981Find the Difference Leetcode Solution139
982Kth Smallest Element in a BST Leetcode Solution139
983Maximum Product Subarray139
984Binary Search Tree Delete Operation139
985Level Order Traversal of Binary Tree139
986Longest Nice Substring LeetCode Solution139
987Newman-Conway Sequence139
988Height of a generic tree from parent array139
989Count pair with Given Sum139
990Maximize Sum of Array after K Negations Leetcode Solution138
991My Calendar I LeetCode Solution138
992Find Maximum of Minimum for Every Window Size in a Given Array138
993Segment Tree138
994Check If a Word Occurs As a Prefix of Any Word in a Sentence Leetcode Solution138
995Asteroid Collision LeetCode Solution138
996K Closest Points to Origin Leetcode Solution138
997Climbing stairs138
998Double the first element and move zero to end137
999Largest Number Leetcode Solution137
1000Maximum Product of Indexes of Next Greater on Left and Right137
1001Boundary Traversal of binary tree137
1002Number Of Longest Increasing Subsequence137
1003Find Duplicate Subtrees137
1004Shortest Completing Word Leetcode Solution137
1005Compute nCr % p137
1006Find the First Circular Tour that visits all the Petrol Pumps137
1007Maximum Length of Repeated Subarray137
1008Largest divisible pairs subset137
1009Depth First Search (DFS) for a Graph137
1010Friends Of Appropriate Ages LeetCode Solution137
1011The Maze III LeetCode Solution137
1012Valid Boomerang Leetcode Solution137
1013Maximum subsequence sum such that no three are consecutive137
1014Merge Sort137
1015Number of palindromic paths in a matrix136
1016Construct Binary Tree from given Parent Array representation136
1017Maximum weight transformation of a given string136
1018Graph Valid Tree LeetCode Solution136
1019Insertion in a Binary Tree136
1020First missing positive136
1021Binary Search Tree136
1022Boolean Parenthesization Problem136
1023String Matching in an Array Leetcode Solution136
1024Kill Process LeetCode Solution136
1025Partition Equal Subset Sum136
1026Maximum Number of Ways to Partition an Array LeetCode Solution136
1027Make The String Great Leetcode Solution136
1028Level order traversal using two Queues136
1029Breadth First Search (BFS) for a Graph136
1030Minimum Index Sum of Two Lists136
1031Serialize and Deserialize Binary Tree136
1032Morris Inorder Traversal136
1033Largest Substring Between Two Equal Characters Leetcode Solution136
1034Construction of Longest Increasing Subsequence (N log N)136
1035Advantages of BST over Hash Table135
1036Count minimum steps to get the given desired array135
1037Decrypt String from Alphabet to Integer Mapping Leetcode Solution135
1038Longest subsequence such that difference between adjacents is one135
1039Find number of pairs in an array such that their XOR is 0135
1040Next Greater Element III LeetCode Solution135
1041K maximum sums of overlapping contiguous sub-arrays135
1042Rearrange an array such that ‘arr[j]’ becomes ‘i’ if ‘arr[i]’ is ‘j’135
1043Build an Array With Stack Operations Leetcode Solution135
1044Scramble String LeetCode Solution135
1045Design Hit Counter LeetCode Solution134
1046Rearrange array such that even positioned are greater than odd134
1047Maximum Sum of 3 Non-Overlapping Subarrays134
1048Custom Sort String Leetcode Solution134
1049Ugly Numbers134
1050Available Captures for Rook Leetcode Solution134
1051Validate Binary Search Tree134
1052Ugly Number II LeetCode Solution133
1053Iterative Depth First Traversal of Graph133
1054Employee Importance LeetCode Solution133
1055Defanging an IP Address LeetCode Solution133
1056Invalid Transactions LeetCode Solution133
1057Add two numbers133
1058Bitwise AND of Numbers Range LeetCode Solution133
1059Implement Trie (Prefix Tree) Leetcode Solution133
1060Balanced Binary Tree133
1061Maximum difference between frequency of two elements such that element having greater frequency is also greater133
1062Generate Parentheses Leetcode Solution132
1063Find Peak Element132
1064Path Sum II LeetCode Solution132
1065Super Ugly Number132
1066Search in Sorted Rotated Array132
1067Regular Expression Matching Regular Expression Matching LeetCode Solution132
1068Recover Binary Search Tree Leetcode Solution132
1069Populating Next Right Pointers in Each Node Leetcode Solution132
1070Move all negative elements to end in order with extra space allowed132
1071Count pairs from two sorted arrays whose sum is equal to a given value x132
1072Lowest Common Ancestor132
1073Maximum length subsequence with difference between adjacent elements as either 0 or 1132
1074Remove Duplicates from Sorted Array II Leetcode Solution131
1075Subarrays with K Different Integers Leetcode Solution131
1076Kth Smallest Element in a Sorted Matrix LeetCode Solution131
1077Find a Peak Element II LeetCode Solution131
1078Determine Whether Matrix Can Be Obtained By Rotation LeetCode Solution131
1079Binary Tree Right Side View LeetCode Solution131
1080Number of Students Doing Homework at a Given Time Leetcode Solution131
1081Largest BST Subtree LeetCode Solution131
1082Root to Leaf path with target sum Leetcode Solutions131
1083Longest Bitonic Subsequence131
1084Number of siblings of a given Node in n-ary Tree130
1085Number of Closed Islands Leetcode Solution130
1086Day of the Year Leetcode Solution130
1087Smallest Common Region Leetcode Solution130
1088Combination Sum IV LeetCode Solution130
1089Maximize Distance to Closest Person LeetCode Solution130
1090Rearrange array such that even index elements are smaller and odd index elements are greater130
1091Clone a Binary Tree with Random Pointers130
1092Minimum Size Subarray Sum130
1093Find whether a subarray is in form of a mountain or not130
1094Find Smallest Range Containing Elements from k Lists129
1095Binary Tree Data Structure129
1096Increasing Triplet Subsequence LeetCode Solution129
1097Distinct Subsequences129
1098Find the minimum distance between two numbers129
1099Serialize and Deserialize Binary Tree LeetCode Solution129
1100Consecutive Characters LeetCode Solution129
1101Level of Each node in a Tree from source node129
1102Find maximum difference between nearest left and right smaller elements129
1103Next Permutation Leetcode Solution129
1104Count Largest Group Leetcode Solution129
1105Remove Palindromic Subsequences Leetcode Solution129
1106Convert BST into a Min-Heap without using array129
1107Kth Smallest Product of Two Sorted Arrays LeetCode Solution129
1108Types of Binary Tree129
1109Minimum Absolute Difference in BST Leetcode Solution129
1110Divisible Pairs Counting128
1111Find Three Element From Different Three Arrays Such That a + b + c = sum128
1112Print all triplets in sorted array that form AP128
1113Remove duplicates from sorted array128
1114Constant time range add operation on an array128
1115Valid Tic-Tac-Toe State LeetCode Solution128
1116Iterative method to find ancestors of a given binary tree128
1117Third Maximum Number Leetcode Solution128
1118Path Sum128
1119Cutting a Rod128
1120Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution128
1121Maximum Product Subarray127
1122Longest Subarray of 1’s After Deleting One Element LeetCode Solution127
1123Reformat The String Leetcode Solution127
1124Products of ranges in an array127
1125Palindrome Permutation LeetCode Solution127
1126Prime Palindrome LeetCode Solution127
1127Sum of Even Numbers After Queries127
1128Cells with Odd Values in a Matrix LeetCode Solution126
1129Bottom View of a Binary Tree126
1130Write Code to Determine if Two Trees are Identical126
1131Mean of Array After Removing Some Elements Leetcode Solution126
1132Print Right View of a Binary Tree126
1133Print Next Greater Number of Q queries126
1134Minimum Score Triangulation of Polygon Leetcode Solution126
1135Thousand Separator Leetcode Solution126
1136Search Insert Position126
1137Topological Sorting125
1138Moser-de Bruijn Sequence125
1139Longest Increasing Consecutive Subsequence125
1140Merge two BSTs with limited extra space125
1141Delete Nodes and Return Forest Leetcode Solution125
1142Search an Element in Sorted Rotated Array125
1143Swap Nodes In Pairs124
1144Construct K Palindrome Strings LeetCode Solution124
1145Priority Queue124
1146Minimum sum of squares of character counts in a given string after removing k characters124
1147Closest Binary Search Tree Value Leetcode Solution124
1148Subset Sum Problem in O(sum) space124
1149Palindromic Substrings Leetcode Solution124
1150Maximum Binary Tree124
1151Red-Black Tree Introduction124
1152Print modified array after executing the commands of addition and subtraction123
1153Check Array Formation Through Concatenation Leetcode Solution123
1154Possible Bipartition LeetCode Solution123
1155Find maximum length Snake sequence123
1156Golomb sequence123
1157Find Two Non-overlapping Sub-arrays Each With Target Sum LeetCode Solution123
1158Bus Routes Leetcode Solution123
1159Diameter of N-Ary Tree LeetCode Solution123
1160Remove Max Number of Edges to Keep Graph Fully Traversable Leetcode Solution122
1161Maximize sum of consecutive differences in a circular array122
1162Search Suggestions System LeetCode Solution122
1163Find Largest Value in Each Tree Row LeetCode Solution122
1164Rotate Array122
1165Maximum Product of Splitted Binary Tree LeetCode Solution122
1166Web Crawler LeetCode Solution122
1167Minimum Sideway Jumps LeetCode Solution122
1168Kth Smallest Number in Multiplication Table Leetcode Solution122
1169Find a sorted subsequence of size 3 in linear time122
1170Queries for Number of Distinct Elements in a Subarray122
1171Transform a BST to Greater sum Tree122
1172Longest Repeated Subsequence121
1173Find the smallest binary digit multiple of given number121
1174Decision Tree121
1175Count even length binary sequences with same sum of first and second half bits121
1176Minimum Cost to Move Chips to The Same Position LeetCode Solution121
1177Compare Strings by Frequency of the Smallest Character Leetcode Solution121
1178Binary Tree to Binary Search Tree Conversion121
1179First Bad Version120
1180Matchsticks to Square Leetcode Solution120
1181Factorial Trailing Zeroes LeetCode Solution120
1182Graph and its representation120
1183Swapping Nodes in a Linked List Leetcode Solution120
1184Convert Sorted Array to Binary Search Tree LeetCode Solutions120
1185Lowest Common Ancestor in Binary Search Tree120
1186Valid Triangle Number119
1187Contiguous Array LeetCode Solution119
1188Maximum sum bitonic subarray119
1189Decrease Elements To Make Array Zigzag LeetCode Solution119
1190Queue Reconstruction by Height119
1191Minimum Moves to Equal Array Elements LeetCode Solution119
1192K’th Largest element in BST using constant extra space119
1193Reverse a Path in BST using Queue119
1194Number of Orders in the Backlog Leetcode Solution119
1195Given a binary tree, how do you remove all the half nodes?118
1196Sum of Left Leaves LeetCode Solution118
1197How to print maximum number of A’s using given four keys118
1198Maximum number of segments of lengths a, b and c118
1199Range Queries for Longest Correct Bracket Subsequence118
1200Lowest Common Ancestor of a Binary Tree Leetcode Solution118
1201Moving Stones Until Consecutive Leetcode Solution118
1202Count Pairs Whose Products Exist in Array118
1203Closest Leaf in a Binary Tree LeetCode Solution118
1204Reformat Date LeetCode Solution118
1205Maximum sum of pairs with specific difference118
1206Array Queries for multiply replacements and product117
1207Kth Smallest Element in a BST117
1208Champagne Tower LeetCode Solution117
1209Guess The Word117
1210Replace two consecutive equal values with one greater116
1211Convert Integer to the Sum of Two No-Zero Integers Leetcode Solution116
1212Filter Restaurants by Vegan-Friendly, Price and Distance Leetcode Solution116
1213Path Crossing Leetcode Solution116
1214Perfect Squares LeetCode Solution115
1215Minimum Swaps To Make Sequences Increasing LeetCode Solution115
1216Flatten 2D Vector LeetCode Solution115
1217Integer Break LeetCode Solution115
1218Concatenation of Array LeetCode Solution115
1219Arithmetic Slices II – Subsequence LeetCode Solution115
1220Range Sum Query using Sparse Table115
1221Design Skiplist LeetCode Solution114
1222Divide Two Integers Leetcode Solution114
1223The kth Factor of n Leetcode Solution114
1224Maximum Depth Of Binary Tree114
1225Write a function to get the intersection point of two Linked Lists114
1226LRU Cache Leetcode Solution114
1227Power of Two114
1228Check if each internal node of a BST has exactly one child114
1229Mean of range in array114
1230Check Completeness of a Binary Tree LeetCode Solution114
1231Maximum sum of a path in a Right Number Triangle114
1232BST to a Tree with Sum of all Smaller Keys114
1233Bold Words in String LeetCode Solution113
1234Sliding Window Median Leetcode Solution113
1235Check if all levels of two Binary Tree are anagrams or not113
1236Largest Plus Sign Leetcode Solution113
1237Queries on Probability of Even or Odd Number in given Ranges113
1238Contiguous Array113
1239Longest Common Prefix Using Word by Word Matching113
1240Valid Perfect Square LeetCode Solution113
1241New 21 Game113
1242Print modified array after multiple array range increment operations113
1243Check for Identical BSTs without building the trees113
1244Maximize Elements Using Another Array113
1245Find Minimum in Rotated Sorted Array II LeetCode Solution113
1246Print n terms of Newman-Conway Sequence112
1247Parallel Courses II LeetCode Solution112
1248Maximum Value at a Given Index in a Bounded Array LeetCode Solution112
1249Print Ancestors of a Given Binary Tree Node Without Recursion112
1250Find k-th smallest element in BST (Order Statistics in BST)111
1251Count Subsets Having Distinct Even Numbers111
1252Find minimum number of merge operations to make an array palindrome111
1253Symmetric Tree LeetCode Solution Leetcode Solution111
1254Merge k Sorted Lists Leetcode Solution111
1255Maximum Product Subarray111
1256Maximum Array from Two given Arrays Keeping Order Same111
1257Graph Cloning111
1258Smallest Range II Leetcode Solution110
1259Count and Toggle Queries on a Binary Array110
1260Minimum Remove to Make Valid Parentheses LeetCode Solution110
1261Missing Number110
1262Check if two nodes are on the same path in a Tree110
1263Number of elements less than or equal to a given number in a given subarray109
1264Next greater element109
1265Verify Preorder Serialization of a Binary Tree109
1266Minimum Time to Collect All Apples in a Tree LeetCode Solution108
1267Excel Sheet Column Title LeetCode Solution108
1268Check If a String Can Break Another String Leetcode Solution108
1269Image Overlap LeetCode Solution108
1270Palindrome Partitioning107
1271Orderly Queue LeetCode Solution107
1272Different Ways to Add Parentheses Leetcode Solution107
1273Min Cost Climbing Stairs LeetCode Solution107
1274Koko Eating Bananas LeetCode Solution107
1275Largest Submatrix With Rearrangements LeetCode Solution105
1276Check if X can give change to every person in the Queue105
1277Newman–Shanks–Williams prime105
1278Peeking Iterator LeetCode Solution105
1279Longest Substring Without Repeating Characters Leetcode Solution104
1280Check in binary array the number represented by a subarray is odd or even104
1281Merge Sorted Array103
1282Range Minimum Query (Square Root Decomposition and Sparse Table)102
1283Array Nesting Leetcode Solution102
1284Maximum Sum Increasing Subsequence101
1285Arranging Coins Leetcode Solution101
1286Encoded String With Shortest Length LeetCode Solution100
1287Maximum product of an increasing subsequence100
1288Find maximum average subarray of k length100
1289Queries for Decimal Values of Subarrays of a Binary Array99
1290Minimum Total Space Wasted With K Resizing Operations LeetCode Solution99
1291Number of indexes with equal elements in given range99
1292Minimum Number of People to Teach LeetCode Solution98
1293Convert to Base -2 LeetCode Solution98
1294Reach a Number LeetCode Solution97
1295Convert a BST to a Binary Tree such that sum of all greater keys is added to every key97
1296Random Pick Index LeetCode Solution97
1297Continuous Subarray Sum LeetCode Solution96
1298Find the Winner of the Circular Game LeetCode Solution96
1299Vertical Order Traversal of Binary Tree LeetCode Solution96
1300Add Two Numbers II Leetcode Solution96
1301Binary Tree to Binary Search Tree Conversion using STL set96
1302Check given array of size n can represent BST of n levels or not96
1303Jump Game IV LeetCode Solution95
1304Palindrome Number LeetCode Solution95
1305Queries on XOR of greatest odd divisor of the range95
1306Insert Delete GetRandom O(1) Leetcode Solution94
1307Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution94
1308Minimum Possible Integer After at Most K Adjacent Swaps On Digits LeetCode Solution94
1309Design Underground System Leetcode Solution90
1310Print Maximum Length Chain of Pairs89
1311Detect Capital Leetcode Solution87
1312Design A Leaderboard Leetcode Solution86
1313Minimum Swaps to Group All 1’s Together Leetcode Solution83
1314Substring with Concatenation of All Words Leetcode Solution83
1315Top K Frequent Elements LeetCode Solution83
1316Binary Tree Inorder Traversal LeetCode Solution81
1317Count Sub Islands LeetCode Solution80
1318Minimum Path Sum Leetcode Solution80
1319Shifting Letters LeetCode Solution79
1320Odd Even Linked List Leetcode Solution77
1321Longest Common Subsequence LeetCode Solution77
1322Find the Town Judge LeetCode Solution76
1323Best Meeting Point LeetCode Solution76
1324Decode String Leetcode Solution76
1325Maximum Population Year LeetCode Solution75
1326Find the Town Judge LeetCode Solution75
1327Sum Root to Leaf Numbers LeetCode Solution72
1328Shortest Unsorted Continuous Subarray LeetCode Solution72
1329Maximum Population Year LeetCode Solution71
1330Rectangle Overlap LeetCode Solution71
1331Design Add and Search Words Data Structure LeetCode Solution70
1332Score of Parenthesis LeetCode Solution67
1333Stone Game IV LeetCode Solution67
1334Flatten Binary Tree to Linked List LeetCode Solution67
1335Insert into a Sorted Circular Linked List LeetCode Solution66
1336Range Sum Query 2D – Immutable LeetCode Solution66
1337Reveal Cards In Increasing Order Leetcode Solution63
1338Is Graph Bipartite? LeetCode Solution62
1339Valid Triangle Number LeetCode Solution62
1340Divide Chocolate LeetCode Solution53
1341Step-By-Step Directions From a Binary Tree Node to Another LeetCode Solution48
1342Range Sum of BST LeetCode Solution45
1343Reverse Integer Leetcode Solution45
1344Sort Colors LeetCode Solution42
1345Find K Closest Elements LeetCode Solution40
1346Maximum Side Length of a Square with Sum Less than or Equal to Threshold LeetCode Solution38
1347Rotate String LeetCode Solution37
1348Excel Sheet Column Number LeetCode Solution37
1349Maximum Size Subarray Sum Equals k Leetcode Solution20
1350H-Index Leetcode Solution19
1351High Five LeetCode Solution18
1352Unique Binary Search Trees LeetCode Solution10
1353Insert Delete GetRandom O(1) – Duplicates allowed LeetCode Solution9
1354Monotonic Array Leetcode Solution7
1355Valid Triangle Number LeetCode Solution7
1356Swim in Rising Water LeetCode Solution4
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