Submission #1419545

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Source Code Expand

#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
typedef long long ll;

int main(){
  int N;
  cin>>N;
  int a[N];
  FOR(i,0,N) cin>>a[i];
  int ans = 0;
  FOR(i,0,N)
  {
    if(a[a[i]-1] == i + 1) ans++;
  }
  cout << ans / 2 << endl;
  return 0;
}

Submission Info

Judge Result