请教如何分析算法的时空复杂度

void Permutation(int k, int n, int* perm) {
    if (k == n - 1) {
        for (int i = 0; i < n; ++i) {
            cout << perm[i] << " ";
        }
        cout << endl;    
    }

    for (int i = k; i < n; ++i) {
        swap(perm[i], perm[k]);
        Permutation(k + 1, n, perm);                                         
        swap(perm[i], perm[k]);
    }
}