LeetCode

Every valid email consists of a local name and a domain name, separated by the '@' sign.

You're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have.

You are given a license key represented as a string s that consists of only alphanumeric characters and dashes.

Given a non-empty array of decimal digits representing a non-negative integer, increment one to the integer.

Given an integer array nums, move all 0's to the end of it while maintaining the relative order of the non-zero elements.

Given an integer array nums and an integer k, return the kth largest element in the array.

Given an array of points where points[i] = xi, yi represents a point on the X-Y plane and an integer k, return the k closest points to the origin

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals

You are given an array of logs. Each log is a space-delimited string of words, where the first word is the identifier.

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

Given an array of integers temperatures represents the daily temperatures, return an array answer

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

Given an array of strings strs, group the anagrams together.

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

Given an m x n matrix, return all elements of the matrix in spiral order.

Given a string s, find the length of the longest substring without repeating characters.

Given two strings s and p, return an array of all the start indices of p's anagrams in s. You may return the answer in any order.

You are given two non-empty linked lists representing two non-negative integers.

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order.

Given the head of a singly linked list, reverse the list, and return the reversed list.

You are keeping score for a baseball game with strange rules.

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

Given the root of a binary tree, return the level order traversal of its nodes' values. (i.e., from left to right, level by level).

Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands.

Given the root of a binary tree, return its maximum depth.

You are given an m x n binary matrix grid.

beginWord and endWord, and a dictionary wordList, return the number of words in the shortest transformation sequence from beginWord to endWord

Given an m x n grid of characters board and a string word, return true if word exists in the grid.

Given a string s that contains parentheses and letters, remove the minimum number of invalid parentheses to make the input string valid.

There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1.

A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below).

You are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money.

You are climbing a staircase. It takes n steps to reach the top.

Given an integer array nums, return the length of the longest strictly increasing subsequence.

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

Given an array nums of distinct integers, return all the possible permutations.

Given an integer array nums of unique elements, return all possible subsets (the power set).

Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent.