389. Find the Difference

• Difficulty: Easy

• Topics: Hash Table, Bit Manipulation

• Similar Questions:

  • Single Number

Problem:

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. </pre>

Solutions:

class Solution {
public:
    char findTheDifference(string s, string t) {
        char ret = 0;
        for (auto c : s) {
            ret ^= c;
        }
        for (auto c : t) {
            ret ^= c;
        }

        return ret;
    }
};