없는 숫자 더하기

import java.util.Arrays;

class Solution {
    public int solution(int[] numbers) {
        int empty = 0;

        Arrays.sort(numbers);

        int[] tenNumbers = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

        for (int i = 0; i < tenNumbers.length; i++) {
            for (int j = 0; j < numbers.length; j++) {
                if (tenNumbers[i] == numbers[j]) {
                    break;
                } else if (tenNumbers[i] != numbers[j]) {
                    if (j == numbers.length - 1) {
                        empty += tenNumbers[i];
                    } else {
                        continue;
                    }
                }
            }
        }
        return empty;
    }
}