Submission #890664

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

#define MAX_N 100005
int N;
int A[MAX_N];

void input()
{
  cin >> N;
  for (size_t i = 0; i < N; i++) {
    cin >> A[i];
    A[i]--;
  }
}

int main()
{

  input();

  int ans = 0;
  for (size_t i = 0; i < N; i++) {
    if(A[A[i]] == i){
      ans++;
    }
  }

  cout << ans/2 << endl;

  return 0;
}

Submission Info

Judge Result