389 - Find the Difference

389. Find the Difference

Problem Statement:

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"

Constraints:

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

Solution:

Java

public char findTheDifference(String s, String t) {
  char c = 0;
  for (int i = 0; i < s.length(); ++i)
    c ^= s.charAt(i);
  for (int i = 0; i < t.length(); ++i)
    c ^= t.charAt(i);
  return c;
}

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