Problem Statement Binary Tree Right Side View LeetCode Solution – Given the root of a binary tree, imagine yourself standing on the right side of it, and return the values of the nodes you can see ordered from top to bottom. Example Test Case 1: Input: root = [1, 2, 3, null, 5, null, …
Problem Statement Zigzag Conversion LeetCode Solution – The string “PAYPALISHIRING” is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I …
Problem Statement Minesweeper LeetCode Solution – Let’s play the minesweeper game (Wikipedia, online game)! You are given an m x n char matrix board representing the game board where: ‘M’ represents an unrevealed mine, ‘E’ represents an unrevealed empty square, ‘B’ represents a revealed blank square that has no adjacent mines (i.e., above, below, left, right, and all …
Problem Statement Find Median from Data Stream LeetCode Solution – The median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value and the median is the mean of the two middle values. For example, for arr = [2,3,4], the median …
Problem Statement : Permutation in String Leetcode Solution – Given two strings s1 and s2, return true if s2 contains a permutation of s1, or false otherwise. In other words, return true if one of s1‘s permutations is the substring of s2. Example : Example 1 Input: s1 = “ab”, s2 = “eidbaooo” Output: true Explanation: s2 contains one permutation of s1 (“ba”). …
Problem Statement Asteroid Collision LeetCode Solution – We are given an array asteroids of integers representing asteroids in a row. For each asteroid, the absolute value represents its size, and the sign represents its direction (positive meaning right, negative meaning left). Each asteroid moves at the same speed. Find out the state …
Problem Statement Longest Increasing Path in a Matrix LeetCode Solution – Given an m x n integers matrix, return the length of the longest increasing path in matrix. From each cell, you can either move in four directions: left, right, up, or down. You may not move diagonally or move outside the boundary (i.e., wrap-around is not allowed). Input: …
Problem Statement The Sort Array by Increasing Frequency LeetCode Solution – “Sort Array by Increasing Frequency” states that you’re given an array of integers, sort the array in increasing order based on the frequency of the values. Two or more values have the same frequency, we need to sort them …
Problem Statement The Partition to K Equal Sum Subsets LeetCode Solution – “Partition to K Equal Sum Subsets” states that you’re given the integer array nums and an integer k, return true if it is possible to have k non-empty subsets whose sums are all equal. Example: Input: nums = [4,3,2,3,5,2,1], k = 4 Output: …
Problem Statement : Number of Closed Islands Leetcode Solution – Given a 2D grid consisting of 0s (land) and 1s (water). An island is a maximal 4-directionally connected group of 0s and a closed island is an island totally (all left, top, right, bottom) surrounded by 1s. Return the number of closed islands. Example : Example 1 Input: grid = [[1,1,1,1,1,1,1,0],[1,0,0,0,0,1,1,0],[1,0,1,0,1,1,1,0],[1,0,0,0,0,1,0,1],[1,1,1,1,1,1,1,0]] Output: 2 Explanation: Islands in gray …