389. Find the Difference(Leetcode每日一题-2020.12.18)_you are given two string s and t

Problem

You are given two strings s and t.

String t is generated by random shuffling string s and then add one more letter at a random position.

Return the letter that was added to t.

Constraints:

• 0 <= s.length <= 1000
• t.length == s.length + 1
• s and t consist of lower-case English letters.

Example1

Input: s = “abcd”, t = “abcde”
Output: “e”
Explanation: ‘e’ is the letter that was added.

Example2

Input: s = “”, t = “y”
Output: “y”

Example3

Input: s = “a”, t = “aa”
Output: “a”

Example4

Input: s = “ae”, t = “aea”
Output: “a”

Solution

class Solution {
public:
    char findTheDifference(string s, string t) {
        int x = 0;
        for (auto c: s) x ^= c;
        for (auto c: t) x ^= c;
        return x;
    }
};
1
2
3
4
5
6
7
8
9