Submission #2170395

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Source Code Expand

#include <bits/stdc++.h>

#define rep(i,n) for(long long int (i)=0;(i)<(int)(n);(i)++)
#define rrep(i,a,b) for(long long int i=(a);i<(b);i++)
#define rrrep(i,a,b) for(long long int i=(a);i>=(b);i--)
#define all(v) (v).begin(), (v).end()
#define pb(q) push_back(q)
#define P pair<int,int>
#define Abs(a,b) max(a,b)-min(a,b)
#define YES(condition) if(condition){cout << "YES" << endl;}else{cout << "NO" << endl;}
#define Yes(condition) if(condition){cout << "Yes" << endl;}else{cout << "No" << endl;}
#define Cout(x) cout<<(x)<<endl
#define POSSIBLE(n) cout << ((n) ? "POSSIBLE" : "IMPOSSIBLE"  ) << endl
#define Possible(n) cout << ((n) ? "Possible" : "Impossible"  ) << endl
#define possible(n) cout << ((n) ? "possible" : "impossible"  ) << endl

typedef long long ll;

using namespace std;

const int INF = 1e9,MOD = 1e9 + 7;
const ll LINF = 1e18;

//long long int kaizyo(long long int hh){
  //  cmp=1;
    //while(hh>1){
      //  cmp=(cmp*hh)%MOD;
        //hh--;
    //}
    //return cmp;
//}

//while(x!=0){
            //sum+=x%10;
           // x/=10;
        //}
        //各桁の和

//pair<int,int> p[100000];
//P r[100000];
//cin >> tmp;
//p[i]=make_pair(tmp,i);
//cout << p[i].second+1 << endl;//ペアの右側つまりiを出力

//s.find(w[i])==string::npos
//findの使い方

//for(int i=0;i<n;i++){
   // b[i]=x%2;
    //x/=2;
  //}二進数

long long int n,cnt=1,ans=0,a[10000000],b,c,cmp,cmpp,m,h,w,x,y,sum=0,pos;
int dy[]={1,0,-1,0};
int dx[]={0,1,0,-1};
string alph("snuke"),alphh("ABCDEFGHIJK"),s;

int main(void){
       cin.tie(0);
    ios::sync_with_stdio(false);

        cin >> n;
       rep(i,n)cin >>a[i];
       rep(i,n){
           if(i+1==a[a[i]-1]){
               ans++;
           }
       }
       Cout(ans/2);
return 0;
}

Submission Info

Judge Result