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.
给定两个字符串 s 和 t，它们只包含小写字母。字符串 t 由字符串 s 随机重排，然后在随机位置添加一个字母。请找出在 t 中被添加的字母。
- 题目要求找出 t 字符串中比 s 字符串多出的一个字符。思路还是利用异或的性质，
X^X = 0，将 s 和 t 依次异或，最终多出来的字符就是最后异或的结果。