摘要：
Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telepho 阅读全文
摘要：
Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. 阅读全文
摘要：
Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of 阅读全文
摘要：
Write a function to find the longest common prefix string amongst an array of strings. 题意：找出所给几个字符串的相同前缀 思路：用第一个字符串和之后的所有字符串进行对比，标示出相同字符串的超尾指针就行 ps：通过 阅读全文
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Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 题意：把罗马数字转变为数字 阅读全文
摘要：
Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 题意：把数字转换为罗马数字 感觉用c的话太麻烦了，所以用Python写了 阅读全文