389. 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.

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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.

Solution

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class Solution {
    public char findTheDifference(String s, String t) {
        int xor = 0;
        
        for (char c : s.toCharArray()) {
            xor = xor ^ c;
        }
        
        for (char c : t.toCharArray()) {
            xor = xor ^ c;
        }
        
        return (char) xor;
    }
}

Solution#

Solution