Submission #399779

#	Time	Username	Problem	Language	Result	Execution time	Memory
399779		my99n	Duathlon (APIO18_duathlon)	C++14	0 / 100	1 ms	204 KiB

count_triplets

#include<bits/stdc++.h>
using namespace std;

long long c (long long n) {
  return (n * n + n) >> 1;
}

long long solve (long long n) {
  if (n == 3) return 1; 
  return solve(n-1) + c(n-2);
}

int main(){
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long n, m; cin >> n >> m;
  if (n < 3) cout << 0 << endl;
  if (n != m) cout << 2ll*solve(n) << endl;
  if (n == m) cout << 2ll * c(n-2) * n << endl;
  return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10