Given a positive integer, return its corresponding column title as appear in an Excel sheet. For example: 1 -> A 2 -> B 3 -> C ... 26 -> Z......

Related to question Excel Sheet Column Title Given a column title as appear in an Excel sheet, return its corresponding column number. For example: A ......

Given an array of strings, group anagrams together. For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return: [ ["ate", "eat","tea"], ["......

Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may a......

Given a sequence of words, check whether it forms a valid word square. A sequence of words forms a valid word square if the kth row and column read th......

Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2. Note: The length of both num1 and num2 is < 5......

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order. E......

Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by strings. You need to h......

LeetCode上的相关题目(easy) 9, 14, 20, 28, 58, 66, 73, 125, 168, 171, 186, 189, 205,242, 246, 266, 290, 293, 344, 345, 383, 387, 389, 408, 409, 412, 415, 422......

You are given a string representing an attendance record for a student. The record only contains the following three characters: 'A' : Absent. 'L' : L......

Given a string s and a non-empty string p, find all the start indices of p's anagrams in s. Strings consists of lowercase English letters only and the......

Count the number of segments in a string, where a segment is defined to be a contiguous sequence of non-space characters. Please note that the string ......

Write a program that outputs the string representation of numbers from 1 to n. But for multiples of three it should output “Fizz” instead of the numbe......

Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters. This......

Given a non-empty string s and an abbreviation abbr, return whether the string matches with the given abbreviation. A string such as "word" contains o......

Given two strings s and t which consist of only lowercase letters. String t is generated by random shuffling string s and then add one more letter at ......

Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the rans......

Write a function that takes a string as input and reverse only the vowels of a string. Example 1: Given s = "hello", return "holle". Example 2: Given ......

Write a function that takes a string as input and returns the string reversed. Example: Given s = "hello", return "olleh". 这道题简单到爆了，给两个解，一个是我刚开始做题时候的，......

You are playing the following Flip Game with your friend: Given a string that contains only these two characters: + and -, you and your friend take tu......