Detect Squares LeetCode Solution

Problem Statement

Detect Squares LeetCode Solution – You are given a stream of points on the X-Y plane. Design an algorithm that:

  • Adds new points from the stream into a data structure. Duplicate points are allowed and should be treated as different points.
  • Given a query point, counts the number of ways to choose three points from the data structure such that the three points and the query point form an axis-aligned square with a positive area.

An axis-aligned square is a square whose edges are all the same length and are either parallel or perpendicular to the x-axis and y-axis.

Implement the DetectSquares class:

  • DetectSquares() Initializes the object with an empty data structure.
  • void add(int[] point) Adds a new point point = [x, y] to the data structure.
  • int count(int[] point) Counts the number of ways to form axis-aligned squares with points point = [x, y] as described above.


Example 1:

Detect Squares LeetCode SolutionPinInput

["DetectSquares", "add", "add", "add", "count", "count", "add", "count"]
[[], [[3, 10]], [[11, 2]], [[3, 2]], [[11, 10]], [[14, 8]], [[11, 2]], [[11, 10]]]


[null, null, null, null, 1, 0, null, 2]


DetectSquares detectSquares = new DetectSquares();
detectSquares.add([3, 10]);
detectSquares.add([11, 2]);
detectSquares.add([3, 2]);
detectSquares.count([11, 10]); // return 1. You can choose:
                               //   - The first, second, and third points
detectSquares.count([14, 8]);  // return 0. The query point cannot form a square with any points in the data structure.
detectSquares.add([11, 2]);    // Adding duplicate points is allowed.
detectSquares.count([11, 10]); // return 2. You can choose:
                               //   - The first, second, and third points
                               //   - The first, third, and fourth points



  • point.length == 2
  • 0 <= x, y <= 1000
  • At most 3000 calls in total will be made to add and count.



 Given p1, try all points p3 (p1 and p3 form diagonal)

  • To compute count(p1):
    • First, We try all points p3 which together with p1, form the diagonal of the non-empty square. This means abs(p1.x-p3.x) == abs(p1.y-p3.y) && abs(p1.x-p3.x) > 0
    • Secondly, Since we have 2 points p1 and p3, we can form a square by computing the positions of the 2 remaining points p2p4.
    • Thirdly, because of the abovep2 = (p1.x, p3.y)
    • Lastly, because of the abovep4 = (p3.x, p1.y)

Detect Squares LeetCode SolutionPin



C++ Program of Detect Squares

class DetectSquares { 
    int cntPoints[1001][1001] = {};
    vector<pair<int, int>> points;

    void add(vector<int> p) {
        points.emplace_back(p[0], p[1]);

    int count(vector<int> p1) {
        int x1 = p1[0], y1 = p1[1], ans = 0;
        for (auto& [x3, y3] : points) {
            if (abs(x1-x3) == 0 || abs(x1-x3) != abs(y1-y3))
            ans += cntPoints[x1][y3] * cntPoints[x3][y1];
        return ans;

Java Program of Detect Squares

class DetectSquares { 
    int[][] cntPoints = new int[1001][1001];
    List<int[]> points = new ArrayList<>();

    public void add(int[] p) {
        cntPoints[p[0]][p[1]] += 1;

    public int count(int[] p1) {
        int x1 = p1[0], y1 = p1[1], ans = 0;
        for (int[] p3 : points) {
            int x3 = p3[0], y3 = p3[1];
            if (Math.abs(x1-x3) == 0 || Math.abs(x1-x3) != Math.abs(y1-y3))
            ans += cntPoints[x1][y3] * cntPoints[x3][y1];
        return ans;

Python Program of Detect Squares

class DetectSquares:
    def __init__(self):
        self.cntPoints = Counter()

    def add(self, point: List[int]) -> None:
        self.cntPoints[tuple(point)] += 1

    def count(self, point: List[int]) -> int:
        ans = 0
        x1, y1 = point
        for (x3, y3), cnt in self.cntPoints.items():
            if abs(x1 - x3) == 0 or abs(x1 - x3) != abs(y1 - y3):
            ans += cnt * self.cntPoints[(x1, y3)] * self.cntPoints[(x3, y1)]
        return ans

Complexity Analysis for Detect Squares LeetCode Solution

Time Complexity

To begin with, the time complexity of the above code is O(1) because no matter how large our input is, we are still going to be running the same functions the same amount of times

Space Complexity

To end, the space complexity of the above code is O(1) because since we are doing only the same functions a constant amount of times, the space will also always be constant

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538Largest Perimeter Triangle Leetcode Solution212
539Is Subsequence Leetcode Solution212
540Jewels and Stones Leetcode Solution212
541Container with Most Water212
542Largest Sum Contiguous Subarray212
543Minimum Delete Operations to make all Elements of Array Same212
544Arrange given numbers to form the biggest number212
545Minimum Moves to Equal Array Elements Leetcode Solution212
546Find Sum of all unique sub-array sum for a given array212
547Gold Mine Problem211
548Group Multiple Occurrence of Array Elements Ordered by first Occurrence211
549Smallest Subarray With all Occurrences of a Most Frequent Element211
550Check if a queue can be sorted into another queue using a stack211
551Excel Sheet Column Title Leetcode Solution211
552Next Greater Frequency Element210
553Find N Unique Integers Sum up to Zero Leetcode Solution210
554Last Stone Weight210
555Isomorphic Strings Leetcode Solution210
556How to check if two given sets are disjoint?210
557Hamming Distance210
558Zigzag Conversion LeetCode Solution210
559Change the Array into Permutation of Numbers From 1 to N210
560Delete Node in a Linked List Leetcode Solution210
561Contiguous Array Leetcode210
562Maximum sum rectangle in a 2D matrix209
563Convert a normal BST to Balanced BST209
564Minimum Bracket Reversals209
565N-th Tribonacci Number Leetcode Solution209
566Distribute Candies to People Leetcode Solution208
567Shuffle an Array208
568Summary Ranges Leetcode Solution208
569Best Time to Buy and Sell Stock208
570Length of Last Word Leetcode Solution208
571Count the number of nodes at given level in a tree using BFS208
572Mobile Numeric Keypad Problem208
573Koko Eating Bananas Leetcode Solution208
574Maximum Distance in Array207
575Implementation of Deque using circular array207
5763Sum Closest LeetCode Solution207
577Minimum Cost to Hire K Workers207
578Valid Anagrams207
579Minimum number of subsets with distinct elements206
580Frog Jump Leetcode Solution206
581Shortest Path in a Grid with Obstacles Elimination LeetCode Solution206
582Find Words That Can Be Formed by Characters Leetcode Solution206
583Trapping Rain Water LeetCode Solution206
584Decode Ways206
585Maximum path sum in a triangle206
586Integer to Roman205
587First negative integer in every window of size k205
588Relative Sort Array Leetcode Solution205
589Rotate Image LeetCode Solution205
590Remove All Occurrences of a Substring LeetCode Solution205
591Find if an Expression has Duplicate Parenthesis or Not205
592Build Array From Permutation Leetcode Solution205
593Number of Provinces Leetcode Solution205
594LRU Cache LeetCode Solution204
595Longest Increasing Subsequence204
596Combinations Leetcode Solution204
597Delete consecutive same words in a sequence204
598Minimum Operations to convert X to Y204
59901 Matrix LeetCode Solution204
600Maximum Number of Occurrences of a Substring Leetcode Solution203
601Word Pattern203
602Iterative Method to find Height of Binary Tree203
603Smallest Good Base203
604Sieve of Eratosthenes203
605Island Perimeter Leetcode Solution203
606Minimum number of distinct elements after removing m items203
607Count all subsequences having product less than K203
608Maximum difference between first and last indexes of an element in array203
609Assign Cookies Leetcode Solution202
610Find minimum difference between any two elements202
611Find the smallest positive integer value that cannot be represented as sum of any subset of a given array202
612XOR Operation in an Array Leetcode Solution202
613Sort Characters By Frequency LeetCode Solution202
614Non-overlapping sum of two sets201
615Stone Game LeetCode201
616Reverse a stack without using extra space in O(n)201
617Bubble sort using two Stacks201
618Convert Sorted Array to Binary Search Tree Leetcode Solution201
619Insert Interval Leetcode Solution201
620Minimum insertions to form a palindrome with permutations allowed201
621Remove Linked List Elements Leetcode Solution201
622Rotate List Leetcode Solution201
623GCD Of Two Numbers201
624Applications of Breadth First Search and Depth First Search200
625Same Tree LeetCode Solution200
626Sum of f(a[i], a[j]) over all pairs in an array of n integers200
627Tracking current Maximum Element in a Stack200
628The Knapsack Problem200
629Permutation in String Leetcode Solution199
630Isomorphic Strings199
631Unique Binary Search Trees199
632Find Largest d in Array such that a + b + c = d199
633Maximum Number of Chocolates to be Distributed Equally Among k Students199
634Defanging an IP Address Leetcode Solution199
635Find the Duplicate Number LeetCode Solution199
636Reorganize String199
637Longest Increasing Path in a Matrix LeetCode Solution198
638Optimal Account Balancing LeetCode Solution198
639Distance Between Bus Stops Leetcode Solution198
640First Unique Character in a String LeetCode Solution198
641K Empty Slots198
642How to Create Mergable Stack?198
643Printing brackets in Matrix Chain Multiplication Problem198
644Count Good Nodes in Binary Tree Leetcode Solution198
645License Key Formatting Leetcode Solution198
646Employee Free Time LeetCode Solution197
647Letter Combinations of a Phone Number197
648Form minimum number from given sequence197
649Minimum Number of Steps to Make Two Strings Anagram Leetcode Solutions196
650Convert an array to reduced form196
651Replace Elements with Greatest Element on Right Side Leetcode Solution196
652Minimum Depth of Binary Tree Leetcode Solution196
653Merge Two Balanced Binary Search Trees195
654Strobogrammatic Number LeetCode Solution195
655Check If It Is a Straight Line Leetcode Solution195
656Painting Fence Algorithm195
657House Robber195
658Reducing Dishes LeetCode Solution195
659Sort Array By Parity LeetCode Solution195
660Convert a Number to Hexadecimal Leetcode Solution195
661Word Wrap Problem195
662Robot Room Cleaner Leetcode Solution195
663Find Pair with Greatest Product in Array195
664Find pairs with given sum such that elements of pair are in different rows195
665Partition Labels LeetCode Solution194
666Kth Missing Positive Number Leetcode Solution194
667Queries for counts of array elements with values in given range194
668Segregate 0s and 1s in an Array194
669Longest Substring with At Most K Distinct Characters LeetCode Solution194
670Maximum Consecutive Numbers Present in an Array194
671Moving Average from Data Stream Leetcode Solution194
672K Empty Slots LeetCode194
673Largest subarray with equal number of 0s and 1s194
674Valid Palindrome II Leetcode Solution193
675String to Integer (atoi) LeetCode Solution193
676Find Maximum Level sum in Binary Tree193
677Longest Substring with At Least K Repeating Characters LeetCode Solution193
678Maximum Product of Two Elements in an Array Leetcode Solution193
679Dynamic Programming Basics192
680Distance of nearest cell having 1 in a binary matrix192
681Valid Palindrome192
682Coin Change Problem192
683Power of Four Leetcode Solution192
684Find the node with minimum value in a Binary Search Tree192
685Longest Span with same Sum in two Binary arrays192
686Partition Array Into Three Parts With Equal Sum Leetcode Solution192
687Reservoir Sampling192
688Best Time to Buy and Sell Stock with Cooldown Leetcode Solution192
689Find the Distance Value Between Two Arrays Leetcode Solution192
690Print the Fibonacci numbers in reverse order192
691Find unique character in a string191
692Remove Invalid Parentheses Leetcode Solution191
693Find the Smallest Divisor given a Threshold Leetcode Solution191
694String Compression LeetCode Solution191
695Sum of All Odd Length Subarrays Leetcode Solution191
696Check If Two String Arrays are Equivalent Leetcode Solution191
697Reverse Only Letters LeetCode Solution190
698Number of Dice Rolls With Target Sum LeetCode Solution190
699Numbers with prime frequencies greater than or equal to k190
700Unique Paths II Leetcode Solution190
701Inorder Successor of a node in Binary Tree190
702Path With Maximum Minimum Value LeetCode Solution190
703Find Leaves of Binary Tree LeetCode Solution190
704Wiggle Sort190
705Binary Tree Maximum Path Sum LeetCode Solution190
706To Lower Case Leetcode Solution190
707Generate all possible sorted arrays from alternate elements of two given sorted arrays190
708Find the largest multiple of 3190
709Flipping an Image LeetCode Solution190
710Sort Array by Increasing Frequency Leetcode Solution189
711Subset Sum Leetcode189
712Rearrange an array in order – smallest, largest, 2nd smallest, 2nd largest189
713Stack Permutations (Check if an array is stack permutation of other)189
714Maximum Number of Coins You Can Get Leetcode Solution189
715Delete Nth node from the end of the given linked list189
716Factorial Trailing Zeroes Leetcode Solution189
717Edit Distance LeetCode Solution189
718Increasing Decreasing String Leetcode Solution189
719Lucky Numbers in a Matrix Leetcode Solution189
720Non-decreasing Array LeetCode Solution188
721Find if Path Exists in Graph Leetcode Solution188
722Bulb Switcher LeetCode Solution188
723Permutation Sequence LeetCode Solution188
724Perform String Shifts Leetcode188
725Snakes and Ladders LeetCode Solution188
726Count quadruples from four sorted arrays whose sum is equal to a given value x188
727Find whether an array is subset of another array188
728Merge Two Binary Trees LeetCode Solution188
729Race Car LeetCode Solution188
730Reversing a Queue using Recursion188
731Ugly Number Leetcode Solution187
732Binary Tree Zigzag Level Order Traversal LeetCode Solution187
733Valid Perfect Square Leetcode Solution187
734BFS vs DFS for Binary Tree187
735Maximum 69 Number Leetcode Solution187
736Find Maximum Depth of Nested Parenthesis in a String187
737Populating Next Right Pointers in Each Node187
738Majority Element II Leetcode Solution187
739Minimum Cost For Tickets Leetcode Solution186
740Recover Binary Search Tree186
741Remove brackets from an algebraic string containing + and – operators186
742Base 7 Leetcode Solution186
743Student Attendance Record I Leetcode Solution186
744Keyboard Row Leetcode Solution186
745Best Meeting Point LeetCode Solution186
746Merge Sorted Array LeetCode Solution186
747Tiling Problem186
748Maximum Length of a Concatenated String with Unique Characters Leetcode Solution186
749String comparison containing wildcards186
750Evaluate Reverse Polish Notation LeetCode Solution186
751Number of NGEs to the Right186
752k-th missing element in increasing sequence which is not present in a given sequence185
753Maximum Product of Three Numbers LeetCode Solution185
754Finding K closest element185
755Elements to be added so that all elements of a range are present in array185
756Print a Binary Tree in Vertical Order185
757Binary Tree zigzag level order Traversal185
758Find Median from Data Stream LeetCode Solution185
759Valid Number185
760Symmetric Tree Leetcode Solution185
761Split a String in Balanced Strings Leetcode Solution185
762Rank Transform of an Array Leetcode Solution185
763Program for Bridge and Torch problem185
764Restore IP Addresses Leetcode Solution185
765Morris Traversal185
766Find All Possible Recipes from Given Supplies LeetCode Solution185
767Word Pattern LeetCode Solution185
768Add and Search Word – Data structure design LeetCode184
769Check If Array Pairs Are Divisible by k LeetCode Solution184
770Priority Queue using doubly linked list184
771Maximum Profit in Job Scheduling Leetcode Solution184
772Special Array With X Elements Greater Than or Equal X Leetcode Solution184
773Binomial Coefficient184
774Number of Days Between Two Dates LeetCode Solution184
775Find All Duplicates in an Array LeetCode Solution184
776Check if Two Expressions With Brackets are Same184
777N-Queens LeetCode Solution184
778Partition to K Equal Sum Subsets Leetcode Solution184
779Brick Wall LeetCode Solution184
780Construct BST from given Preorder Traversal184
781Regular Expression Matching184
782Jump Game183
783Search in a Binary Search Tree Leetcode Solution183
784Hamming Distance Leetcode Solution183
785Sorted Linked List to Balanced BST183
786Growable array based stack183
787Decompress Run-Length Encoded List Leetcode Solution183
788Minimum Distance Between BST Nodes Leetcode Solution183
789Minimize Maximum Pair Sum in Array LeetCode Solution183
790Kth ancestor of a node in binary tree182
791Total Numbers With no Repeated Digits in a Range182
792Minimum Height Trees182
793Minimum sum of multiplications of n numbers182
794Largest rectangular sub-matrix whose sum is 0182
795Check for Palindrome after every character replacement Query182
796One Edit Distance LeetCode Solution182
797Largest Rectangle in Histogram LeetCode Solution182
798Top K Frequent Words LeetCode Solution182
799Sort an array according to the order defined by another array182
800Merge K Sorted Linked Lists182
801Nearest Exit from Entrance in Maze LeetCode Solution182
802Maximum Depth of N-ary Tree Leetcode Solution182
803Maximum Difference Between Increasing Elements LeetCode Solution182
804Invert Binary Tree LeetCode Solution182
805Form Minimum Number From Given Sequence182
806Balanced Expression with Replacement181
807Circular Queue181
808Number of Islands II LeetCode Solution181
809Remove Nth Node From End of List Leetcode Solution181
810Minimum Time Visiting All Points Leetcode Solution181
811Identify and Mark Unmatched Parenthesis in an Expression181
812Queue based approach for first non-repeating character in a stream181
813Final Prices With a Special Discount in a Shop Leetcode Solution181
814Nested List Weight Sum II LeetCode Solution180
815Count items common to both the lists but with different prices180
816Relative Ranks Leetcode Solution180
817Minimum time required to rot all oranges180
818Repeated Substring Pattern LeetCode Solution180
819Maximum Nesting Depth of the Parentheses Leetcode Solution180
820Linked List Cycle180
821Diagonal Traversal of Binary Tree180
822Transpose Graph180
823Longest Subarray Having Count of 1s One More than Count of 0s180
824Deletion in a Binary Tree179
825Search a 2D Matrix II Leetcode Solution179
826Crawler Log Folder Leetcode Solution179
827Minimum Swaps to Make Strings Equal Leetcode Solution179
828Given an Array of Pairs Find all Symmetric Pairs in it179
829Minimum Number of Taps to Open to Water a Garden LeetCode Solution179
830Number Complement Leetcode Solution178
831Minimum Jumps to Reach Home LeetCode Solution178
832Course Schedule II – LeetCode178
833Sort Array By Parity II Leetcode Solution178
834Clone Graph LeetCode Solution178
835Split Array Into Consecutive Subsequences178
836Subsequence of Size K With the Largest Even Sum LeetCode Solution178
837Subarray Product Less Than K LeetCode Solution178
838Daily Temperatures Leetcode Solution178
839Permutation Coefficient178
840Check if an Array is Stack Sortable177
841Binary Search Tree Search and Insertion177
842A Space Optimized DP solution for 0-1 Knapsack Problem177
843Last Stone Weight II LeetCode Solution177
844Make Two Arrays Equal by Reversing Sub-arrays Leetcode Solution177
845Find Maximum Sum Possible Equal Sum of Three Stacks177
846Lemonade Change Leetcode Solution177
847Insert Delete GetRandom177
848Find all permuted rows of a given row in a matrix177
849LCS (Longest Common Subsequence) of three strings177
850Design Browser History LeetCode Solution177
851Iterative Preorder Traversal177
852Check if stack elements are pairwise consecutive177
853Missing Element in Sorted Array LeetCode Solution177
854Distinct adjacent elements in an array177
855Reorder Data in Log Files LeetCode Solution177
856Check if a given array can represent Preorder Traversal of Binary Search Tree176
857Guess Number Higher or Lower LeetCode Solution176
858Path with maximum average value176
859Sliding Window Maximum176
860Minimum number of jumps to reach end176
861Count Distinct Elements in Every Window of Size K176
862Tree Traversal (Preorder, Inorder & Postorder)176
863Subset with sum divisible by m176
864Valid Parentheses Leetcode Solution176
865Can Place Flowers LeetCode Solution175
866Remove Duplicates from Sorted List LeetCode Solution175
867Dividing Array into Pairs With Sum Divisible by K175
868Union and Intersection of two Linked Lists175
869Convert BST to Min Heap175
870Design a Stack With Increment Operation Leetcode Solution175
871An Interesting Method to generate Binary Numbers from 1 to n175
872Partition List Leetcode Solution175
873Alien Dictionary LeetCode Solution175
874Minimum Sum Path in a Triangle175
875Interval Tree175
876Remove Duplicates from Sorted List II175
877Level order Traversal in Spiral Form174
878Get Maximum in Generated Array Leetcode Solution174
879Minesweeper LeetCode Solution174
880Brightest Position on Street LeetCode Solution174
881Spiral Matrix II Leetcode Solution174
882Find the subarray with least average174
883Infix to Postfix174
884Count ways to reach the nth stair using step 1, 2 or 3174
885Minimum swaps to make sequences increasing174
886Sequences of given length where every element is more than or equal to twice of previous174
887Check whether a given Binary Tree is Complete or not173
888Number of Distinct Islands Leetcode Solution173
889Water Bottles Leetcode Solution173
890Find distance between two nodes of a Binary Tree173
891Find all triplets with zero sum173
892Rearrange Array such that arr[i] >= arr[j] if i is even and arr[i] <= arr[j] if i is odd and j < i173
893Friends Pairing Problem173
894Diagonal Traverse LeetCode Solution173
895GCDs of given index ranges in an array173
896Range sum queries without updates173
897Find the Only Repetitive Element Between 1 to N-1173
898Sum of nearest smaller and greater number173
899Pattern Occurrences using Stack173
900Least Number of Unique Integers after K Removals Leetcode Solution173
901Maximum size subarray sum equals k173
902Sorted Array to Balanced BST173
903Matrix Chain Multiplication173
904Guess Number Higher or Lower II173
905Sort Colors173
906Maximum Score After Splitting a String Leetcode Solution173
907Check if any two intervals overlap among a given set of intervals172
908Median of Two Sorted Arrays172
909Insert into a Binary Search Tree Leetcode Solution172
910Set Matrix Zeroes Leetcode Solution172
911Range LCM Queries172
912Best Time to Buy and Sell Stock with Transaction Fee Leetcode Solution172
913Lexicographical Numbers Leetcode Solution172
914Shortest Word Distance Leetcode Solution172
915Delete And Earn172
916Time Based Key-Value Store LeetCode Solution171
917A program to check if a binary tree is BST or not171
918Count Negative Numbers in a Sorted Matrix LeetCode Solution171
919Robot Bounded In Circle LeetCode Solution171
920Diagonal Traversal LeetCode Solution171
921Averages of Levels in Binary Tree171
922Alien Dictionary171
923Difference Array | Range update query in O(1)171
924Rearrange an Array Such that arr[i] is equal to i171
925Destination City Leetcode Solution171
926All Unique Triplets that Sum up to a Given Value171
927Iterative Postorder Traversal Using Two Stacks171
928Product of Array Except Self LeetCode Solution170
929K’th Largest Element in BST when modification to BST is not allowed170
930Count Submatrices With All Ones LeetCode Solution170
931Rearrange Spaces Between Words Leetcode Solution170
932Construct Complete Binary Tree from its Linked List Representation170
933Binary Tree Longest Consecutive Sequence LeetCode Solution170
934Three way partitioning of an array around a given range170
935Construct the Rectangle Leetcode Solution170
936Check if the given array can represent Level Order Traversal of Binary Search Tree170
937My Calendar I LeetCode Solution170
938Vertical sum in a given binary tree169
939Three Consecutive Odds Leetcode Solution169
940Minimum Height Trees LeetCode Solution169
941Merge Two Sorted Lists Leetcode169
942Queue using Stacks169
943Spiral Matrix III LeetCode Solution169
944Convert Sorted List to Binary Search Tree169
945Count Subarrays with Same Even and Odd Elements169
946Trim a Binary Search Tree169
947Binary array after M range toggle operations169
948Find Common Characters Leetcode Solution169
949Palindrome Partitioning Leetcode Solution169
950Maximum Frequency Stack Leetcode Solution169
951Intersection of Two Linked Lists LeetCode Solution169
952Number of Equivalent Domino Pairs Leetcode Solution169
953Special Positions in a Binary Matrix Leetcode Solution169
954Strongly Connected Component168
955Remove Duplicates from Sorted List II LeetCode Solution168
956Word Break168
957BFS for Disconnected Graph168
958Largest area rectangular sub-matrix with equal number of 1’s and 0’s168
959Analyze User Website Visit Pattern LeetCode Solution168
960Count Primes in Ranges167
961Kth Smallest Element in a BST Leetcode Solution167
962Sign of the Product of an Array LeetCode Solution167
963Longest Palindromic Subsequence167
964Construct BST from its given Level Order Traversal167
965Queries for GCD of all numbers of an array except elements in a given range167
9663 Sum167
968Create Maximum Number167
969Climbing stairs167
970Merging Intervals166
971Maximum Product Subarray166
972Count pair with Given Sum166
973Stone Game II Leetcode166
974Unique Paths II166
975Number of palindromic paths in a matrix166
976Count subarrays where second highest lie before highest166
977Symmetric Tree166
978Combination Sum IV LeetCode Solution166
979Longest subsequence such that difference between adjacents is one166
980Maximize Sum of Array after K Negations Leetcode Solution166
981Reverse Nodes in K-Group165
982Depth First Search (DFS) for a Graph165
983Serialize and Deserialize Binary Tree165
984Breadth First Search (BFS) for a Graph165
985The Maze III LeetCode Solution165
986Longest Nice Substring LeetCode Solution165
987Design Hit Counter LeetCode Solution165
988Largest Number Leetcode Solution165
989Print Fibonacci sequence using 2 variables165
990Find Maximum of Minimum for Every Window Size in a Given Array165
991Valid Boomerang Leetcode Solution164
992Maximum Product of Indexes of Next Greater on Left and Right164
993Asteroid Collision LeetCode Solution164
994Find the First Circular Tour that visits all the Petrol Pumps164
995Can Make Arithmetic Progression From Sequence Leetcode Solution164
996Binary Search Tree Delete Operation164
997Maximum Length of Repeated Subarray164
998Find number of pairs in an array such that their XOR is 0164
999Consecutive Characters LeetCode Solution163
1000Graph Valid Tree LeetCode Solution163
1001Maximum Subarray Sum Excluding Certain Elements163
1002K maximum sums of overlapping contiguous sub-arrays163
1003Palindrome Partitioning163
1004Kth Smallest Element in a Sorted Matrix LeetCode Solution163
1005String Matching in an Array Leetcode Solution163
1006Next Permutation Leetcode Solution163
1007Scramble String LeetCode Solution163
1008K Closest Points to Origin Leetcode Solution163
1009Count pairs from two sorted arrays whose sum is equal to a given value x163
1010Find the Difference Leetcode Solution162
1011Height of a generic tree from parent array162
1012Find postorder traversal of BST from preorder traversal162
1013Collect maximum points in a grid using two traversals162
1014The Painter’s Partition Problem162
1015Balanced Binary Tree162
1016Level Order Traversal of Binary Tree162
1017Maximum Sum of 3 Non-Overlapping Subarrays162
1018Minimum Index Sum of Two Lists162
1019Decrypt String from Alphabet to Integer Mapping Leetcode Solution162
1020Validate Binary Search Tree162
1021Length of Longest Fibonacci Subsequence162
1022Shuffle 2n integers as without using extra space162
1023Shortest Completing Word Leetcode Solution162
1024Maximum difference between frequency of two elements such that element having greater frequency is also greater161
1025Merge Sort161
1026Largest divisible pairs subset161
1027Newman-Conway Sequence161
1028Remove Duplicates from Sorted Array II Leetcode Solution161
1029Generate Parentheses Leetcode Solution161
1030Find Duplicate Subtrees161
1031Maximum Number of Ways to Partition an Array LeetCode Solution161
1032Rearrange an array such that ‘arr[j]’ becomes ‘i’ if ‘arr[i]’ is ‘j’161
1033Segment Tree161
1034Maximum length subsequence with difference between adjacent elements as either 0 or 1161
1035Print Next Greater Number of Q queries161
1036Available Captures for Rook Leetcode Solution161
1037Invalid Transactions LeetCode Solution161
1038Binary Search Tree160
1039Number Of Longest Increasing Subsequence160
1040Custom Sort String Leetcode Solution160
1041Advantages of BST over Hash Table160
1042Construction of Longest Increasing Subsequence (N log N)160
1043Largest Substring Between Two Equal Characters Leetcode Solution160
1044Next Greater Element III LeetCode Solution160
1045Find a Peak Element II LeetCode Solution160
1046Boolean Parenthesization Problem160
1047Insertion in a Binary Tree160
1048First missing positive160
1049Make The String Great Leetcode Solution160
1050Construct Binary Tree from given Parent Array representation160
1051Move all negative elements to end in order with extra space allowed159
1052Rearrange array such that even positioned are greater than odd159
1053Count minimum steps to get the given desired array159
1054Compute nCr % p159
1055Iterative Depth First Traversal of Graph159
1056Bitwise AND of Numbers Range LeetCode Solution159
1057Friends Of Appropriate Ages LeetCode Solution159
1058Boundary Traversal of binary tree159
1059Check If a Word Occurs As a Prefix of Any Word in a Sentence Leetcode Solution159
1060Kill Process LeetCode Solution158
1061Rearrange array such that even index elements are smaller and odd index elements are greater158
1062Determine Whether Matrix Can Be Obtained By Rotation LeetCode Solution158
1063Double the first element and move zero to end158
1064Maximum subsequence sum such that no three are consecutive158
1065Path Sum II LeetCode Solution158
1066Largest BST Subtree LeetCode Solution158
1067Subarrays with K Different Integers Leetcode Solution158
1068Build an Array With Stack Operations Leetcode Solution158
1069Minimum Size Subarray Sum158
1070Morris Inorder Traversal157
1071Regular Expression Matching Regular Expression Matching LeetCode Solution157
1072Recover Binary Search Tree Leetcode Solution157
1073Defanging an IP Address LeetCode Solution157
1074Find Peak Element157
1075Employee Importance LeetCode Solution157
1076Add two numbers157
1077Remove Palindromic Subsequences Leetcode Solution157
1078Level order traversal using two Queues157
1079Partition Equal Subset Sum156
1080Find maximum difference between nearest left and right smaller elements156
1081Lowest Common Ancestor156
1082Ugly Number II LeetCode Solution156
1083Maximum weight transformation of a given string156
1084Palindrome Permutation LeetCode Solution156
1085Smallest Common Region Leetcode Solution156
1086Print Right View of a Binary Tree156
1087Palindromic Substrings Leetcode Solution155
1088Increasing Triplet Subsequence LeetCode Solution155
1089Maximize Distance to Closest Person LeetCode Solution155
1090Longest Bitonic Subsequence155
1091Remove duplicates from sorted array155
1092Ugly Numbers155
1093Binary Tree Right Side View LeetCode Solution155
1094Implement Trie (Prefix Tree) Leetcode Solution155
1095Number of Closed Islands Leetcode Solution155
1096Super Ugly Number155
1097Populating Next Right Pointers in Each Node Leetcode Solution154
1098Valid Tic-Tac-Toe State LeetCode Solution154
1099Path Sum154
1100Bus Routes Leetcode Solution154
1101Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution154
1102Sum of Even Numbers After Queries154
1103Find whether a subarray is in form of a mountain or not154
1104Divisible Pairs Counting153
1105Find the minimum distance between two numbers153
1106Print all triplets in sorted array that form AP153
1107Binary Tree Data Structure153
1108Search in Sorted Rotated Array153
1109Reformat The String Leetcode Solution153
1110Moser-de Bruijn Sequence153
1111Number of siblings of a given Node in n-ary Tree153
1112Find Three Element From Different Three Arrays Such That a + b + c = sum153
1113Thousand Separator Leetcode Solution153
1114Mean of Array After Removing Some Elements Leetcode Solution152
1115Find Smallest Range Containing Elements from k Lists152
1116Cells with Odd Values in a Matrix LeetCode Solution152
1117Kth Smallest Product of Two Sorted Arrays LeetCode Solution152
1118Number of Students Doing Homework at a Given Time Leetcode Solution152
1119Count Largest Group Leetcode Solution152
1120Day of the Year Leetcode Solution152
1121Level of Each node in a Tree from source node152
1122Search Insert Position151
1123Iterative method to find ancestors of a given binary tree151
1124Serialize and Deserialize Binary Tree LeetCode Solution151
1125Clone a Binary Tree with Random Pointers151
1126Distinct Subsequences151
1127Products of ranges in an array151
1128Root to Leaf path with target sum Leetcode Solutions151
1129Constant time range add operation on an array150
1130Longest Increasing Consecutive Subsequence150
1131Compare Strings by Frequency of the Smallest Character Leetcode Solution150
1132Third Maximum Number Leetcode Solution150
1133Find Two Non-overlapping Sub-arrays Each With Target Sum LeetCode Solution150
1134Prime Palindrome LeetCode Solution150
1135Find maximum length Snake sequence150
1136Minimum Absolute Difference in BST Leetcode Solution150
1137Topological Sorting150
1138Longest Repeated Subsequence149
1139Construct K Palindrome Strings LeetCode Solution149
1140Bottom View of a Binary Tree149
1141Queries for Number of Distinct Elements in a Subarray149
1142Maximum Product Subarray149
1143Convert BST into a Min-Heap without using array149
1144Maximum Depth Of Binary Tree149
1145Web Crawler LeetCode Solution148
1146Maximum Product of Splitted Binary Tree LeetCode Solution148
1147Write Code to Determine if Two Trees are Identical148
1148Diameter of N-Ary Tree LeetCode Solution148
1149Print modified array after executing the commands of addition and subtraction148
1150Minimum sum of squares of character counts in a given string after removing k characters148
1151Longest Subarray of 1’s After Deleting One Element LeetCode Solution148
1152Rotate Array148
1153Count even length binary sequences with same sum of first and second half bits148
1154Priority Queue148
1155Closest Leaf in a Binary Tree LeetCode Solution147
1156Search an Element in Sorted Rotated Array147
1157Find a sorted subsequence of size 3 in linear time147
1158Find Largest Value in Each Tree Row LeetCode Solution147
1159Delete Nodes and Return Forest Leetcode Solution147
1160Minimum Score Triangulation of Polygon Leetcode Solution147
1161Closest Binary Search Tree Value Leetcode Solution147
1162Cutting a Rod147
1163Subset Sum Problem in O(sum) space147
1164Golomb sequence147
1165Contiguous Array LeetCode Solution146
1166Minimum Cost to Move Chips to The Same Position LeetCode Solution146
1167Swap Nodes In Pairs146
1168Maximize sum of consecutive differences in a circular array146
1169Reformat Date LeetCode Solution146
1170Search Suggestions System LeetCode Solution146
1171Matchsticks to Square Leetcode Solution146
1172Minimum Sideway Jumps LeetCode Solution145
1173Decision Tree145
1174Red-Black Tree Introduction145
1175Count Pairs Whose Products Exist in Array145
1176K’th Largest element in BST using constant extra space145
1177Transform a BST to Greater sum Tree145
1178Possible Bipartition LeetCode Solution145
1179Kth Smallest Number in Multiplication Table Leetcode Solution145
1180Given a binary tree, how do you remove all the half nodes?145
1181Minimum Moves to Equal Array Elements LeetCode Solution145
1182Minimum Swaps To Make Sequences Increasing LeetCode Solution145
1183Merge two BSTs with limited extra space144
1184Binary Tree to Binary Search Tree Conversion144
1185First Bad Version144
1186Sum of Left Leaves LeetCode Solution144
1187Check Array Formation Through Concatenation Leetcode Solution144
1188Decrease Elements To Make Array Zigzag LeetCode Solution144
1189Maximum Value at a Given Index in a Bounded Array LeetCode Solution144
1190Path Crossing Leetcode Solution144
1191Find the smallest binary digit multiple of given number144
1192Maximum Binary Tree144
1193Remove Max Number of Edges to Keep Graph Fully Traversable Leetcode Solution144
1194Reverse a Path in BST using Queue144
1195Valid Triangle Number143
1196Convert Integer to the Sum of Two No-Zero Integers Leetcode Solution143
1197Perfect Squares LeetCode Solution143
1198Maximum number of segments of lengths a, b and c143
1199Print n terms of Newman-Conway Sequence143
1200Maximum sum of pairs with specific difference143
1201Replace two consecutive equal values with one greater143
1202Number of Orders in the Backlog Leetcode Solution142
1203Convert Sorted Array to Binary Search Tree LeetCode Solutions142
1204Queue Reconstruction by Height142
1205Maximum sum bitonic subarray142
1206Concatenation of Array LeetCode Solution142
1207Factorial Trailing Zeroes LeetCode Solution142
1208Divide Two Integers Leetcode Solution142
1209Sliding Window Median Leetcode Solution142
1210Valid Perfect Square LeetCode Solution141
1211Swapping Nodes in a Linked List Leetcode Solution141
1212New 21 Game141
1213Lowest Common Ancestor in Binary Search Tree140
1214Champagne Tower LeetCode Solution140
1215Integer Break LeetCode Solution140
1216Maximum sum of a path in a Right Number Triangle140
1217Lowest Common Ancestor of a Binary Tree Leetcode Solution140
1218Kth Smallest Element in a BST140
1219How to print maximum number of A’s using given four keys140
1220Merge k Sorted Lists Leetcode Solution139
1221Array Queries for multiply replacements and product139
1222Moving Stones Until Consecutive Leetcode Solution139
1223Find minimum number of merge operations to make an array palindrome139
1224Flatten 2D Vector LeetCode Solution139
1225Guess The Word139
1226Queries on Probability of Even or Odd Number in given Ranges139
1227Longest Common Prefix Using Word by Word Matching139
1228Filter Restaurants by Vegan-Friendly, Price and Distance Leetcode Solution138
1229Range Sum Query using Sparse Table138
1230Graph and its representation138
1231Mean of range in array138
1232Maximum Array from Two given Arrays Keeping Order Same138
1233Check if all levels of two Binary Tree are anagrams or not138
1234Range Queries for Longest Correct Bracket Subsequence137
1235LRU Cache Leetcode Solution137
1236Missing Number137
1237Print modified array after multiple array range increment operations137
1238BST to a Tree with Sum of all Smaller Keys137
1239Contiguous Array137
1240Design Skiplist LeetCode Solution137
1241Find Minimum in Rotated Sorted Array II LeetCode Solution137
1242Maximum Sum Increasing Subsequence137
1243Maximize Elements Using Another Array137
1244Bold Words in String LeetCode Solution136
1245Min Cost Climbing Stairs LeetCode Solution136
1246Count Subsets Having Distinct Even Numbers136
1247Minimum Remove to Make Valid Parentheses LeetCode Solution136
1248Write a function to get the intersection point of two Linked Lists136
1249The kth Factor of n Leetcode Solution136
1250Largest Plus Sign Leetcode Solution136
1251Maximum Product Subarray136
1252Check in binary array the number represented by a subarray is odd or even135
1253Graph Cloning135
1254Power of Two134
1255Arithmetic Slices II – Subsequence LeetCode Solution134
1256Check if each internal node of a BST has exactly one child134
1257Different Ways to Add Parentheses Leetcode Solution134
1258Parallel Courses II LeetCode Solution134
1259Find k-th smallest element in BST (Order Statistics in BST)134
1260Minimum Time to Collect All Apples in a Tree LeetCode Solution133
1261Check for Identical BSTs without building the trees133
1262Check if two nodes are on the same path in a Tree133
1263Image Overlap LeetCode Solution132
1264Smallest Range II Leetcode Solution132
1265Verify Preorder Serialization of a Binary Tree132
1266Symmetric Tree LeetCode Solution Leetcode Solution132
1267Check Completeness of a Binary Tree LeetCode Solution132
1268Print Ancestors of a Given Binary Tree Node Without Recursion132
1269Excel Sheet Column Title LeetCode Solution131
1270Orderly Queue LeetCode Solution131
1271Next greater element130
1272Koko Eating Bananas LeetCode Solution130
1273Longest Substring Without Repeating Characters Leetcode Solution130
1274Merge Sorted Array129
1275Arranging Coins Leetcode Solution129
1276Vertical Order Traversal of Binary Tree LeetCode Solution128
1277Largest Submatrix With Rearrangements LeetCode Solution128
1278Count and Toggle Queries on a Binary Array128
1279Number of elements less than or equal to a given number in a given subarray128
1280Array Nesting Leetcode Solution127
1281Palindrome Partitioning127
1282Palindrome Number LeetCode Solution127
1283Add Two Numbers II Leetcode Solution126
1284Newman–Shanks–Williams prime126
1285Check If a String Can Break Another String Leetcode Solution126
1286Queries for Decimal Values of Subarrays of a Binary Array125
1287Find the Winner of the Circular Game LeetCode Solution125
1288Peeking Iterator LeetCode Solution125
1289Check if X can give change to every person in the Queue125
1290Insert Delete GetRandom O(1) Leetcode Solution125
1291Maximum product of an increasing subsequence125
1292Range Minimum Query (Square Root Decomposition and Sparse Table)124
1293Find maximum average subarray of k length124
1294Encoded String With Shortest Length LeetCode Solution122
1295Number of Subsequences That Satisfy the Given Sum Condition LeetCode solution122
1296Continuous Subarray Sum LeetCode Solution121
1297Check given array of size n can represent BST of n levels or not121
1298Minimum Possible Integer After at Most K Adjacent Swaps On Digits LeetCode Solution120
1299Binary Tree to Binary Search Tree Conversion using STL set120
1300Jump Game IV LeetCode Solution120
1301Number of indexes with equal elements in given range120
1302Random Pick Index LeetCode Solution119
1303Minimum Number of People to Teach LeetCode Solution119
1304Reach a Number LeetCode Solution119
1305Convert a BST to a Binary Tree such that sum of all greater keys is added to every key118
1306Minimum Total Space Wasted With K Resizing Operations LeetCode Solution117
1307Convert to Base -2 LeetCode Solution116
1308Queries on XOR of greatest odd divisor of the range115
1309Design A Leaderboard Leetcode Solution115
1310Design Underground System Leetcode Solution114
1311Shifting Letters LeetCode Solution112
1312Print Maximum Length Chain of Pairs111
1313Detect Capital Leetcode Solution111
1314Minimum Swaps to Group All 1’s Together Leetcode Solution110
1315Top K Frequent Elements LeetCode Solution109
1316Count Sub Islands LeetCode Solution108
1317Minimum Path Sum Leetcode Solution107
1318Monotonic Array Leetcode Solution105
1319Substring with Concatenation of All Words Leetcode Solution104
1320Odd Even Linked List Leetcode Solution104
1321Longest Common Subsequence LeetCode Solution102
1322Binary Tree Inorder Traversal LeetCode Solution101
1323Decode String Leetcode Solution101
1324Maximum Population Year LeetCode Solution100
1325Find the Town Judge LeetCode Solution100
1326Shortest Unsorted Continuous Subarray LeetCode Solution95
1327Best Meeting Point LeetCode Solution94
1328Rectangle Overlap LeetCode Solution94
1329Maximum Population Year LeetCode Solution93
1330Find the Town Judge LeetCode Solution92
1331Sum Root to Leaf Numbers LeetCode Solution91
1332Insert into a Sorted Circular Linked List LeetCode Solution91
1333Flatten Binary Tree to Linked List LeetCode Solution90
1334Design Add and Search Words Data Structure LeetCode Solution89
1335Stone Game IV LeetCode Solution88
1336Range Sum Query 2D – Immutable LeetCode Solution87
1337Is Graph Bipartite? LeetCode Solution87
1338Reveal Cards In Increasing Order Leetcode Solution87
1339Valid Triangle Number LeetCode Solution86
1340Score of Parenthesis LeetCode Solution85
1341Divide Chocolate LeetCode Solution81
1342Step-By-Step Directions From a Binary Tree Node to Another LeetCode Solution75
1343Range Sum of BST LeetCode Solution69
1344Reverse Integer Leetcode Solution66
1345Rotate String LeetCode Solution64
1346Find K Closest Elements LeetCode Solution64
1347Sort Colors LeetCode Solution63
1348Maximum Side Length of a Square with Sum Less than or Equal to Threshold LeetCode Solution61
1349Excel Sheet Column Number LeetCode Solution57
1350Maximum Size Subarray Sum Equals k Leetcode Solution50
1351Camelcase Matching Leetcode Solution45
1352H-Index Leetcode Solution45
1353Valid Anagram Leetcode Solution44
1354Most Stones Removed with Same Row or Column LeetCode Solution43
1355Container With Most Water LeetCode Solution43
1356Sliding Window Maximum LeetCode Solution42
1357Group Anagrams LeetCode Solution42
1358High Five LeetCode Solution41
1359Next Permutation LeetCode Solution41
1360Binary Search LeetCode Solution40
1361Find Peak Element LeetCode Solution40
1362Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution39
1363Paint House LeetCode Solution37
1364Valid Triangle Number LeetCode Solution36
1365Minimum Number of Arrows to Burst Balloons LeetCode Solution36
1366Flatten Binary Tree to Linked List LeetCode Solution35
1367Next Greater Element I Leetcode Solution35
1368Isomorphic Strings LeetCode Solution35
1369Unique Binary Search Trees LeetCode Solution35
1370Group Shifted Strings Leetcode Solution34
1371Sentence Screen Fitting LeetCode Solution33
1372Swim in Rising Water LeetCode Solution32
1373Count Good Nodes in Binary Tree LeetCode Solution32
1374The Number of Weak Characters in the Game LeetCode Solution32
1375Insert Delete GetRandom O(1) – Duplicates allowed LeetCode Solution32
1376Peak Index in a Mountain Array LeetCode Solution31
1377Closest Binary Search Tree Value II LeetCode Solution31
1378Split Linked List in Parts Leetcode Solution27
1379Single Element in a Sorted Array LeetCode Solution27
1380All Possible Full Binary Trees LeetCode Solution27
1381Validate Stack Sequences LeetCode Solution26
1382Minimum Increment to Make Array Unique Leetcode Solution25
1383Max Sum of Two Non-Overlapping Subarrays LeetCode Solution25
1384Lowest Common Ancestor of a Binary Search Tree Leetcode Solution25
1385Find First and Last Position of Element in Sorted Array LeetCode Solution24
1386Best Time to Buy and Sell Stock IV LeetCode Solution24
1387Greatest Sum Divisible by Three LeetCode Solution24
1388Implement strStr() LeetCode Solution23
1389Trapping Rain Water II LeetCode Solution23
1390Implement Rand10() Using Rand7() Leetcode Solution22
1391Stone Game IV LeetCode Solution22
1392Break a Palindrome LeetCode Solution22
1393Detect Squares LeetCode Solution21
1394Contains Duplicate LeetCode Solution20
1395Fibonacci Number LeetCode Solution20
1396Invert Binary Tree LeetCode Solution19
1397Remove All Ones With Row and Column Flips Leetcode Solution19
1398Design Bounded Blocking Queue LeetCode Solution18
1399Reverse Nodes in k-Group LeetCode Solution17
1400Minimum Number of Operations to Move All Balls to Each Box LeetCode Solution16
1401Total Hamming Distance LeetCode Solution14
1402Candy LeetCode Solution13
1403Unique Paths III LeetCode Solution11
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