[LeetCode]--387. 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 = "leetcode"
return 0.

s = "loveleetcode",
return 2.

Note: You may assume the string contain only lowercase letters.

用数组，简单粗暴，把字符个数都记录下来，最后遍历一下原来的字符串，判断再这个数组里面的个数就行。

public int firstUniqChar1(String s) {
        if (s == null || s.length() == 0)
            return -1;
        int[]