#include #include #include using namespace std; void f(int n, int r, vector& vt, int start, int count) { if (count == 0) { for (int i = 0; i < vt.size(); i ++ ) { cout << vt[i]; } cout << endl; } else { for (int i = start; i >= r; i--) { vt.push_back(i); f(n, r - 1, vt, i - 1, count - 1); vt.pop_back(); } } } int main() { int n, r; cin >> n >> r; vector vt; f(n, r, vt, n, r); int t = 1; for (int i = n; i > n - r; i--) { t *= i; } for (int i = 2; i <= r; i++) { t /= i; } cout << "total=" << t << endl; return 0; }