0387-first-unique-character-in-a-string.adoc

387. First Unique Character in a String

{leetcode}/problems/first-unique-character-in-a-string/[LeetCode - First Unique Character in a String^]

还是要善用 Map 来统计字符数量！

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 letters.

思路分析

通过解法是再次遍历字符串，思考如何遍历字母表来获取第一个唯一字符的位置。

一刷

link:{sourcedir}/_0387_FirstUniqueCharacterInAString.java[role=include]

二刷

link:{sourcedir}/_0387_FirstUniqueCharacterInAString_2.java[role=include]

参考资料

1. 387. 字符串中的第一个唯一字符 - 哈希表，清晰图解

2. 387. 字符串中的第一个唯一字符 - 官方题解