Submission #891407

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Source Code Expand

#include<iostream>

#define REP(i,a,b) for(int i=(int)(a);i<(int)(b);++i)

using namespace std;

int nlist[100010];

int main(){
  int cnt = 0;
  int N;
  cin>>N;
  REP(i,0,N){
    cin>>nlist[i];
    nlist[i]--;
  }
  
  REP(i,0,N){
    if(i == nlist[nlist[i]]) cnt++;
  }
  cout<<cnt/2<<endl;
  return 0;
}

Submission Info

Judge Result