Find the Difference

Find the Difference

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.

Example 1:

Input: s = "abcd", t = "abcde"
Output: "e"
Explanation: 'e' is the letter that was added.

Example 2:

Input: s = "", t = "y"
Output: "y"

Example 3:

Input: s = "a", t = "aa"
Output: "a"

Example 4:

Input: s = "ae", t = "aea"
Output: "a"

Constraints:

• 0 <= s.length <= 1000

• t.length == s.length + 1

• s and t consist of lower-case English letters.

Solutions

🧠 Cpp

#define all(x) (x).begin(), (x).end()
class Solution
{

public:
    char findTheDifference(string s, string t)
    {
        std::sort(all(s));
        std::sort(all(t));

        string diff;
        std::set_difference(all(t),
                            all(s),
                            back_inserter(diff));

        return diff.front();
    }
};