вариант 2 пермутации

public class Test {
    public static void permutate(int ind, int []perm) {
        int n = perm.length;
        if (ind == n) {
            for (int i = 0 ; i < n; ++i) {
                System.out.print(perm[i] + "\t");
            }
            System.out.println();
            return;
        }
        for (int i = 0; i < n; ++i) {
            boolean flag = false;
            for (int k = 0; k < ind; ++k) {
                if (perm[k] == i) {
                    flag = true;
                    break;
                }
            }
            if (!flag) {
                perm[ind] = i;
                permutate(ind + 1, perm);
            }
        }
    }

    public static void main(String []args) {
        int []perm = {-1, -1, -1,  -1, -1};
        permutate(0, perm);
    }
}