_389.java

package com.fishercoder.solutions;
/**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 class _389 {
    public char findTheDifference(String s, String t) {
        int[] counts = new int[128];
        char[] schars = s.toCharArray();
        char[] tchars = t.toCharArray();
        for(int i = 0; i < schars.length; i++){
            counts[schars[i]]++;
        }
        for(int i = 0; i < tchars.length; i++){
            counts[tchars[i]]--;
        }
        char result = 'a';
        for(int i = 0; i < 128; i++){
            if(counts[i] != 0) result = (char) i;
        }
        return result;
    }
}