[LeetCode]--389. 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.

用数组记录字符的老办法。

public char findTheDifference(String s, String t) {
        int[] count = new int[