Leetcode: 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.

O（N）time, O(1) space

public class Solution {
    public char findTheDifference(String s, String t) {
        // Initialize variables to store sum of ASCII codes for 
        // each string
        int charCodeS = 0, charCodeT = 0;
        // Iterate through both strings and char codes
        for (int i = 0; i < s.length(); ++i) charCodeS += (int)s.charAt(i);
        for (int i = 0; i < t.length(); ++i) charCodeT += (int)t.charAt(i);
        // Return the difference between 2 strings as char
        return (char)(charCodeT - charCodeS);
    }
}