Commander Lambda is all about efficiency, including using her bunny prisoners for manual labor. But no one’s been properly monitoring the labor shifts for a while, and they’ve gotten quite mixed up. You’ve been given the task of fixing them, but after you wrote up new shifts, you realized that some prisoners had been transferred to a different block and aren’t available for their assigned shifts. And manually sorting through each shift list to compare against prisoner block lists will take forever - remember, Commander Lambda loves efficiency!

Given two almost identical lists of prisoner IDs x and y where one of the lists contains an additional ID, write a function solution(x, y) that compares the lists and returns the additional ID.

For example, given the lists x = [13, 5, 6, 2, 5] and y = [5, 2, 5, 13], the function solution(x, y) would return 6 because the list x contains the integer 6 and the list y doesn’t. Given the lists x = [14, 27, 1, 4, 2, 50, 3, 1] and y = [2, 4, -4, 3, 1, 1, 14, 27, 50], the function solution(x, y) would return -4 because the list y contains the integer -4 and the list x doesn’t.

In each test case, the lists x and y will always contain n non-unique integers where n is at least 1 but never more than 99, and one of the lists will contain an additional unique integer which should be returned by the function. The same n non-unique integers will be present on both lists, but they might appear in a different order, like in the examples above. Commander Lambda likes to keep her numbers short, so every prisoner ID will be between -1000 and 1000.

Test cases

Your code should pass the following test cases. Note that it may also be run against hidden test cases not shown here.

Input:

(int list) x = [13, 5, 6, 2, 5]
(int list) y = [5, 2, 5, 13]

Output:

(int) 6

Input:

(int list) x = [14, 27, 1, 4, 2, 50, 3, 1]
(int list) y = [2, 4, -4, 3, 1, 1, 14, 27, 50]

Output:

(int) -4

Solutions

class Solution {
    public static int solution(int[] x, int[] y) {
        int ans = 0;
        for (int i = 0; i < x.length; i++) {
            ans ^= x[i];
        }
        for (int i = 0; i < y.length; i++) {
            ans ^= y[i];
        }
        return ans;
    }

    public static void main(String[] args) {
        int[] x1 = {13, 5, 6, 2, 5}, y1 = {5, 2, 5, 13};
        System.out.println(Solution.solution(x1, y1));

        int[] x2 = {14, 27, 1, 4, 2, 50, 3, 1}, y2 = {2, 4, -4, 3, 1, 1, 14, 27, 50};
        System.out.println(Solution.solution(x2, y2));
    }
}
def solution(x, y):
    diff = list(set(x) ^ set(y))
    return diff[0]

if __name__ == "__main__":
    x1, y1 = [13, 5, 6, 2, 5], [5, 2, 5, 13]
    print(solution(x1, y1))

    x2, y2 = [14, 27, 1, 4, 2, 50, 3, 1], [2, 4, -4, 3, 1, 1, 14, 27, 50]
    print(solution(x2, y2))