Problem Statement: Candy LeetCode Solution: There are n children standing in a line. Each child is assigned a rating value given in the integer array ratings. You are giving candies to these children subjected to the following requirements: Each child must have at least one candy. Children with a higher rating get more …
Problem Statement: Unique Paths III LeetCode Solution: You are given an m x n integer array grid where grid[i][j] could be: 1 representing the starting square. There is exactly one starting square. 2 representing the ending square. There is exactly one ending square. 0 representing empty squares we can walk over. -1 representing obstacles that we cannot walk over. Return the …
Problem Statement: Invert Binary Tree LeetCode Solution : Given the root of a binary tree, invert the tree, and return its root. An inverted form of a Binary Tree is another Binary Tree with left and right children of all non-leaf nodes interchanged. You may also call it the mirror of the input tree. …
Problem Statement Validate Stack Sequences LeetCode Solution – Given two integer arrays pushed and popped each with distinct values, return true if this could have been the result of a sequence of push and pop operations on an initially empty stack, or false otherwise. Example 1: Input: pushed = [1,2,3,4,5], popped = [4,5,3,2,1] Output: true Explanation: We …
Problem Statement: Implement strStr() LeetCode Solution – Implement strStr(). Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Clarification: What should we return when needle is an empty string? This is a great question to ask during an interview. For the purpose of this problem, we …
Problem Statement: Count Good Nodes in Binary Tree LeetCode Solution: Given a binary tree root, a node X in the tree is named good if in the path from the root to X there are no nodes with a value greater than X. Return the number of good nodes in the binary tree. Example 1: Input: root = [3,1,4,3,null,1,5] …
Problem Statement: Implement Rand10() Using Rand7() Leetcode Solution – Given the API rand7() that generates a uniform random integer in the range [1, 7], write a function rand10() that produces a uniform random integer in the range [1, 10]. You can only call the API rand7(), and you shouldn’t call any other …
Problem Statement: Contains Duplicate LeetCode Solution says that- Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct. Example 1: Input: nums = [1,2,3,1] Output: true Example 2: Input: nums = [1,2,3,4] Output: false Example 3: Input: nums = [1,1,1,3,3,4,3,2,4,2] Output: …
Problem Statement: Reverse Nodes in k-Group LeetCode Solution – Given the head of a linked list, reverse the nodes of the list k at a time, and return the modified list. k is a positive integer and is less than or equal to the length of the linked list. If the number of nodes is …
Problem Statement: Single Element in a Sorted Array LeetCode Solution says that – You are given a sorted array consisting of only integers where every element appears exactly twice, except for one element which appears exactly once. Return the single element that appears only once. Your solution must run in O(log n) time …