目录 # 前端与算法 leetcode 387. 字符串中的第一个唯一字符 题目描述 概要 提示 解析 解法一:双循环 解法二:Set法单循环 算法 传入测试用例的运行结果 执行结果 GitHub仓库 查看更多 # 前端与算法 leetcode 387. 字符串中的第一个唯一字符 题目描述 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",…

387. 字符串中的第一个唯一字符 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) { //fast int n = s.length(); for(int i = 'a'; i…

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 lowerca…

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,…

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…

题目: 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. Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -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…

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…

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. 给定一个字符串,查找其中的第一个非重复字符并返回其索引.如果它不存在,返回-1. 例子: s =“leetc…