Problem Statement : Decrease Elements To Make Array Zigzag LeetCode Solution – Given an array nums of integers, a move consists of choosing any element and decreasing it by 1. An array A is a zigzag array if either: Every even-indexed element is greater than adjacent elements, ie. A[0] > A[1] < A[2] > A[3] < A[4] > … …
Problem Statement Filter Restaurants by Vegan-Friendly, Price, and Distance Leetcode Solution – Given the array restaurants where restaurants[i] = [idi, ratingi, veganFriendlyi, pricei, distancei]. You have to filter the restaurants using three filters. The veganFriendly filter will be either true (meaning you should only include restaurants with veganFriendlyi set it to true) or false (meaning you can include any …
Problem Statement Count Submatrices With All Ones LeetCode Solution – We are given an m x n binary matrix and are asked to return the number of submatrices that have all ones. Examples and Explanations Example 1: Input: mat = [[1,0,1],[1,1,0],[1,1,0]] Output: 13 Explanation: There are 6 rectangles of side …
Problem Statement Brightest Position on Street LeetCode Solution – We are asked to assume a number line representing a street. This street contains lamp(s) on it. We are given a 2D integer array “lights”. Each lights[i] = [position_i, range_i] indicates that there is a street lamp on position_i which can …
Problem Statement Clone Graph LeetCode Solution – We are given a reference of a node in a connected undirected graph and are asked to return a deep copy of the graph. A deep copy is basically a clone where no node present in the deep copy should have the reference …
Problem Statement Minimum Height Trees LeetCode Solution – We are given a tree of n nodes labelled from 0 to n-1 as a 2D array “edges” where edge[i] = [a_i, b_i] indicates that there is an undirected edge between the two nodes a_i and b_i in the tree. We have …
Problem Statement Kth Smallest Element in a Sorted Matrix LeetCode Solution – We are given a matrix of size n where each of the rows and columns is sorted in ascending order. We are asked to return the kth smallest element in the matrix. Note that it is the kth …
Problem Statement Minimum Sideway Jumps LeetCode Solution – There is a 3 lane road of length n that consists of n + 1 points labeled from 0 to n. A frog starts at point 0 in the second lane and wants to jump to point n. However, there could be obstacles along the way. You are given an array obstacles of length n + 1 where each obstacles[i] (ranging from 0 to 3) …
Problem Statement Construct Binary Tree from Preorder and Postorder Traversal LeetCode Solution – Given two integer arrays, preorder and postorder where preorder is the preorder traversal of a binary tree of distinct values and postorder is the postorder traversal of the same tree, reconstruct and return the binary tree. If there exist multiple answers, you can return any of them. Input: preorder …
Problem Statement Number of Dice Rolls With Target Sum LeetCode Solution – You have n dice and each die has k faces numbered from 1 to k. Given three integers n, k, and target, return the number of possible ways (out of the kn total ways) to roll the dice so the sum of the face-up numbers equals target. Since the answer may be …