[LeetCode] Find the Difference 寻找不同

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.

s

[LeetCode] Find the Difference 寻找不同

原文：http://www.cnblogs.com/grandyang/p/5816418.html