LeetCode 844. Backspace String Compare
Description https://leetcode.com/problems/backspace-string-compare/ Given two strings S and T, return if they are equal when both are typed into empty text editors. # means a backspace character. Example…
LeetCode 876. Middle of the Linked List
Description https://leetcode.com/problems/middle-of-the-linked-list/ Given a non-empty, singly linked list with head node head, return a middle node of linked list. If there are two middle…
LeetCode 49. Group Anagrams
Description https://leetcode.com/problems/group-anagrams/ Given an array of strings, group anagrams together. Example: Input: [“eat”, “tea”, “tan”, “ate”, “nat”, “bat”], Output: […
LeetCode 384. Shuffle an Array
Description https://leetcode.com/problems/shuffle-an-array/ Shuffle a set of numbers without duplicates. Example: // Init an array with set 1, 2, and 3.…
LeetCode 202. Happy Number
Description https://leetcode.com/problems/happy-number/ Write an algorithm to determine if a number is “happy”. A happy number is a number defined by…
30-Day LeetCoding Challenge
LeetCode is running the 30-Day LeetCoding Challenge to solve a frequently-asked interview problem. Week 1: April 1st–April 7th Single Number Happy Number…
LeetCode 198. House Robber
Description https://leetcode.com/problems/house-robber/ You are a professional robber planning to rob houses along a street. Each house has a certain amount…
LeetCode 88. Merge Sorted Array
Description https://leetcode.com/problems/merge-sorted-array/ You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.…
LeetCode 98. Validate Binary Search Tree
Description https://leetcode.com/problems/validate-binary-search-tree/ Given the root of a binary tree, determine if it is a valid binary search tree (BST). A valid BST is defined as…
LeetCode 237. Delete Node in a Linked List
Description https://leetcode.com/problems/delete-node-in-a-linked-list/ Write a function to delete a node in a singly-linked list. You will not be given access to the head of the list, instead…