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.
找出第一次出现的不重复的字符
public class Solution { public int firstUniqChar(String s) { //97-122 int[] map = new int[123]; int i=0; int length = s.length(); for(i=0;i<length;i++) { map[s.charAt(i)]++; } for(i=0;i<length;i++) { if(map[s.charAt(i)] == 1) return i; } return -1; } }
除了两次for循环，暂时没有想到N时间复杂度的解法。
原文：http://www.cnblogs.com/linkstar/p/5958600.html