Submission #1789902

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Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;
ll c[51][51];
void comb_table(int n) {
  for (int i = 0; i <= n; i++) {
    c[i][0] = 1LL;
    c[i][i] = 1LL;
    for (int j = 1; j < i; j++) {
      c[i][j] = c[i - 1][j - 1] + c[i - 1][j];
    }
  }
}
int main(void) {
  int n, a, b;
  cin >> n >> a >> b;
  vector<ll> v(n);
  for (int i = 0; i < n; i++) {
    cin >> v[i];
  }
  sort(v.begin(), v.end(), greater<int>());
  double sum = 0.0;
  for (int i = 0; i < a; i++) {
    sum += v[i];
  }
  cout.precision(20);
  cout << sum / a << endl;
  int cnt1 = 0, cnt2 = 0;
  for (int i = 0; i < n; i++) {
    if (v[i] == v[a - 1]) {
      cnt1++;
      if (i < a) {
        cnt2++;
      }
    }
  }
  comb_table(n);
  ll ans = 0LL;
  if (cnt2 != a) {
    ans = c[cnt1][cnt2];
  } else {
    for (int i = a; i <= b; i++) {
      ans += c[cnt1][i];
    }
  }
  cout << ans << endl;
  return 0;
}

Submission Info

Judge Result