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.

分析:将字符串s和字符串t的字符个数标记在hash1和hash2数组中,然后比较hash1和hash2,值不同的那个字符即为所求~