题目
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.
答案
class Solution {
public int firstUniqChar(String s) {
int[] freq = new int[256];
for(int i = 0; i < s.length(); i++) freq[s.charAt(i)]++;
for(int i = 0; i < s.length(); i++) if(freq[s.charAt(i)] == 1) return i;
return -1;
}
}
