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: Find First and Last Position of Element in Sorted Array LeetCode Solution says that – given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If target is not found in the array, return [-1, -1]. You must write an algorithm with O(log n) runtime complexity. …
Problem Statement Find Peak Element LeetCode Solution says that – A peak element is an element that is strictly greater than its neighbors. Given a 0-indexed integer array nums, find a peak element, and return its index. If the array contains multiple peaks, return the index to any of the peaks. You may imagine …
Problem Statement Group Anagrams LeetCode Solution Says that – Given an array of strings strs, group the anagrams together. You can return the answer in any order. An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. Example 1: …
Problem Statement Sliding Window Maximum LeetCode Solution Says that – You are given an array of integers nums, and there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time …
Problem Statement Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution – Pairs of Songs With Total Durations Divisible by 60 LeetCode Solution says that – You are given a list of songs where the ith song has a duration of time[i] seconds. Return the number of pairs of songs for which …
Problem Statement Valid Anagram Leetcode Solution – Given two strings s and t, return true if t is an anagram of s, and false otherwise. An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. Example 1: Input: s = “anagram”, t = “nagaram” Output: …
Problem Statement Next Permutation LeetCode Solution – A permutation of an array of integers is an arrangement of its members into a sequence or linear order. For example, for arr = [1,2,3], the following are considered permutations of arr: [1,2,3], [1,3,2], [3,1,2], [2,3,1]. The next permutation of an array of integers is the next lexicographically greater permutation of …
Problem Statement Next Greater Element I Leetcode Solution – The next greater element of some element x in an array is the first greater element that is to the right of x in the same array. You are given two distinct 0-indexed integer arrays nums1 and nums2, where nums1 is a subset of nums2. For each 0 <= i < nums1.length, find the index j such that nums1[i] == nums2[j] and determine …
Problem Statement Find K Closest Elements LeetCode Solution – Given a sorted integer array arr, two integers k and x, return the k closest integers to x in the array. The result should also be sorted in ascending order. An integer a is closer to x than an integer b if: |a – x| < |b – x|, or |a – x| == |b – …