LeetCode 387. 字符串中的第一个唯一字符 java

示例 1:

s = "leetcode"
返回 0.

s = "loveleetcode",
返回 2.

JAVA 代码：

class Solution {
    public int firstUniqChar(String s) {
        int index = s.length();
		for (char k = 'a'; k <= 'z'; k++) {
			int p1 = s.indexOf(k);// -1 不存在
			int p2 = s.lastIndexOf(k);
			if (p1 == p2 && p1 != -1) {
				index = Math.min(index, p1);
			}
		}
		if (index == s.length()) {
			return -1;
		}
		return index;
    }
}