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 lowerca…

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…

Problem: Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Example: s = "leetcode" return 0. s = "loveleetcode", return 2. 本题的第一想法是开一个字母表计数器,遍历string s中的元素,并利用计数器对每一个字母计…

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…

题目描述: 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. 解题思路: 开个26个数的数组,然后先对字符串过一遍,统计每个字母出现的次数,然后从头再国一遍,…

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…

最近公司搬家了,有两天没写了,今天闲下来了,继续开始算法之路. leetcode的题目如下: 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: Y…

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…

The ability to debug and overall thinking need to improve 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…

Difficulty:easy  More:[目录]LeetCode Java实现 Description https://leetcode.com/problems/first-unique-character-in-a-string/ 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 =…