Description
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.
Solution
HashTable
class Solution {
public int firstUniqChar(String s) {
char[] count = new char[26];
for (int i = 0; i < s.length(); ++i) {
++count[s.charAt(i) - 'a'];
}
for (int i = 0; i < s.length(); ++i) {
if (count[s.charAt(i) - 'a'] == 1) {
return i;
}
}
return -1;
}
}
