Noitapeli

#include <iostream>
#include <algorithm>
using namespace std;

#define max(a, b) (((a)>(b))?(a):(b))
#define min(a, b) (((a)<(b))?(a):(b))

long long nCr(int n, int k) {
  long long a = 1;
  for (int i = n; i > max(k, n-k); i--) {
    a *= i;
  }
  for (int i = 2; i <= min(n-k, k); i++) {
    a /= i;
  }
  return a;
}

int main() {
  int n;
  cin >> n;

  int a[n+1];
  for (int i = 1; i <= n; i++) a[i] = 0;
  
  long long c = nCr(n, 3);
  for (int i = 1; i <= n; i++) {
    int j;
    cin >> j;
    c -= n-2-a[i]-a[j];
    a[i]++;
    a[j]++;
  }
  cout << c << "\n";
}

Test 1

Group: 1

Verdict: WRONG ANSWER

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: WRONG ANSWER

Test 4

Group: 1

Verdict: WRONG ANSWER

Test 5

Group: 1

Verdict: WRONG ANSWER

Test 6

Group: 2

Verdict: WRONG ANSWER

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: WRONG ANSWER

Test 9

Group: 2

Verdict: WRONG ANSWER

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: WRONG ANSWER

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: WRONG ANSWER

Test 14

Group: 3

Verdict: WRONG ANSWER

Test 15

Group: 3

Verdict: WRONG ANSWER