给定一个字符串,找到它的第一个不重复的字符,并返回它的索引.如果不存在,则返回 -1. 案例: s = "leetcode" 返回 0. s = "loveleetcode", 返回 2. 注意事项:您可以假定该字符串只包含小写字母. class Solution { public: int firstUniqChar(string s) { int len = s.size(); map<char, int> check; for(int i = 0;…

Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: s = "leetcode" return 0. s = "loveleetcode", return 2. Note: You may assume the string contain only lowercase…

题目标签:String, HashMap 题目给了我们一个 string,让我们找出 第一个 唯一的 char. 设立一个 hashmap,把 char 当作 key,char 的index 当作value. 遍历string,如果这个 char 没有在 map 里,说明第一次出现,存入 char,index:                    如果这个 char 已经在 map 里,说明不是第一次出现,而且我们不在乎这种情况,更新 char, -1. 遍历hashmap,把最小的 inde…

给定一个字符串,找到它的第一个不重复的字符,并返回它的索引.如果不存在,则返回 -1.案例:s = "leetcode"返回 0.s = "loveleetcode",返回 2.注意事项:您可以假定该字符串只包含小写字母.详见:https://leetcode.com/problems/first-unique-character-in-a-string/description/ C++: class Solution { public: int firstUniq…

1.1 Implement an algorithm to determine if a string has all unique characters. What if you cannot use additional data structure? 这道题让我们判断一个字符串中是否有重复的字符,要求不用特殊的数据结构,这里应该是指哈希表之类的不让用.像普通的整型数组应该还是能用的,这道题的小技巧就是用整型数组来代替哈希表,在之前Bitwise AND of Numbers Range 数…

Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: s = "leetcode" return 0. s = "loveleetcode", return 2. Note: You may assume the string contain only lowercase…

Description Find the first unique character in a given string. You can assume that there is at least one unique character in the string. Example For "abaccdeff", return 'b'. 解题:返回仅出现一次,并且排在最前面的那个元素,而不是返回第一个不同的元素,一开始理解错了.如果仅仅对于ASCII中的256个字符,可以用数组…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/first-unique-character-in-a-string/description/ 题目描述 Given a string, find the first non-repeating character in it and return it's index. I…

1.单纯的Unicode 转码 String a = "\u53ef\u4ee5\u6ce8\u518c"; a = new String(a.getBytes("UTF-16"),"Unicode"); 2.String 字符串中含有 Unicode 编码时,转为UTF-8 public static String decodeUnicode(String theString) { char aChar; int len = theString…

387. First Unique Character in a String Easy Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: s = "leetcode" return 0. s = "loveleetcode", return 2. Note: You…