Find the Difference

Problem Statement - link #

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.

Examples #

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 #

class Solution {
public:
    char findTheDifference(string a, string b) {
      sort(a.begin(), a.end());
      sort(b.begin(), b.end());
      for(int i=0; i<a.size(); i++)
        if(a[i] != b[i]) return b[i];
      return b.back();
    }
};