leetcode389.Find The Difference

Given two strings s and t which consist of only lowercase letters.

String t is generated by random shuffling string s and then add one more letter at a random position.

Find the letter that was added in t.

Example:

Input:
s = "abcd"
t = "abcde"

Output:
e

Explanation:
'e' is the letter that was added.

    public char findTheDifference(String s, String t) {
        int[] count = new int[26];
        for(int i = 0 ; i<t.length() ; i++) {
            if(i != t.length()-1) {
                count[s.charAt(i)-'a']++;
            }
            count[t.charAt(i)-'a']--;
        }
        for(int i = 0 ; i<count.length ; i++) {
            if(count[i] != 0) {
                return (char)('a' + i);
            }
        }
        return 'a';
    }

    public char findTheDifference2(String s, String t){
        int value = 0;
        for(int i = 0 ; i<s.length() ; i++) {
            value -= s.charAt(i);
            value += t.charAt(i);
        }
        char result = (char)(value + t.charAt(t.length()-1)); 
        return result;
    }