Function toString

code/other/nth_permutation.test.cpp:1–9

string toString(vector<int> p) {
  stringstream ss;
  for (int i = 0; i < size(p); i++) {
    if (i != 0) ss << ",";
    ss << p[i];
  }

  return ss.str();
}

void test() {
  assert_equal(string("0,1,2"), toString(nth_permutation(3, 0)));