Combinations w/ Index Requirements

public class Permu {

    public static void swap(int i1, int i2, int[][] digits) {
        int[] oldV1 = digits[i1];
        digits[i1] = digits[i2];
        digits[i2] = oldV1;
    }

    public static void recurse(int n, int[][] digits) {
        if (n == 1) {
            boolean Approved = true;
            for (int i = 0; i < digits.length; i++) {
                int[] v = digits[i];
                boolean Approved2 = false;
                for (int i2 = 1; i2 < v.length; i2++) {
                    if (v[i2] == i) {
                        Approved2 = true;
                    }
                }
                if (Approved2 == false) {
                    Approved = false;
                    break;
                }
            }
            if (Approved == true) {
                System.out.println(digits.length);
                for (int i = 0; i < digits.length; i++) {
                    System.out.print(digits[i][0]);
                }
                System.out.print("\n");
            }
            return;
        }
        for (int i = 0; i < n-1; i++) {
            recurse(n-1, digits);
            if (n % 2 == 0) {
                swap(i, n-1, digits);
            } else {
                swap(0, n-1, digits);
            }
        }
        recurse(n-1, digits);
    }

    public static void main(String[] args) {
        int[][] Digits = new int[][]{{2, 0, 3}, {9, 2, 3}, {7, 1}, {3, 0, 1, 2, 3}}; //Format: {{Value, AllowedIndex, AllowedIndex2...}, {Value, AllowedIndex, AllowedIndex2...}...}

        recurse(4, Digits);
    }
}