LeetCode-in-Java
387. First Unique Character in a String
Easy
Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1.
Example 1:
Input: s = “leetcode”
Output: 0
Example 2:
Input: s = “loveleetcode”
Output: 2
Example 3:
Input: s = “aabb”
Output: -1
Constraints:
1 <= s.length <= 105sconsists of only lowercase English letters.
Solution
public class Solution {
public int firstUniqChar(String s) {
int ans = Integer.MAX_VALUE;
for (char i = 'a'; i <= 'z'; i++) {
int ind = s.indexOf(i);
if (ind != -1 && ind == s.lastIndexOf(i)) {
ans = Math.min(ans, ind);
}
}
if (ans == Integer.MAX_VALUE) {
return -1;
}
return ans;
}
}