LeetCode C++ 389. Find the Difference【位操作】簡單

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.

題意：t 字符串是 s 中的字符打亂後，再加一個額外的字符形成的。

思路：和136. Single Number一樣的思路和做法。

代碼：

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

效率：

執行用時：4 ms, 在所有 C++ 提交中擊敗了76.72% 的用戶
內存消耗：6.6 MB, 在所有 C++ 提交中擊敗了100.00% 的用戶