Submission #891092

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Source Code Expand

#include<cstdio>
#include<vector>
#include<string>
#include<algorithm>
#include<iostream>
#include<map>
#include<set>


#define reps(i,f,n) for(int i=f;i<int(n);i++)
#define rep(i,n) reps(i,0,n)

using namespace std;

const int N = 111111;

int main()
{
	int n;
	cin>>n;
	
	int a[N];
	rep(i,n){
		cin>>a[i];
		a[i]--;
	}
	
	int cnt = 0;
	
	rep(i,n){
		if(a[a[i]]==i)cnt++;
	}
	
	printf("%d\n",cnt/2);
	
	
	
}

Submission Info

Judge Result