__Meng

摘要： Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), ..., (an, bn) which makes sum of 阅读全文

摘要： You are given a string representing an attendance record for a student. The record only contains the following three characters: A student could be re 阅读全文

摘要： 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 阅读全文

摘要： 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 阅读全文

摘要： Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there ar 阅读全文

摘要： The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11.11 is read off 阅读全文

摘要： Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the 阅读全文

摘要： 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 阅读全文

摘要： Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. Subscribe to see which companies asked thi 阅读全文

摘要： Given a word, you need to judge whether the usage of capitals in it is right or not. We define the usage of capitals in a word to be right when one of 阅读全文