Submission #891779

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
#define fs first
#define sc second
#define MAX 100000
#define pb push_back
#define mp make_pair
#define MOD 1000000007
typedef long long Int;
typedef pair<Int,Int> pii;
typedef vector<Int> vi;
typedef vector<pii> vii;
Int arr[MAX+5],cnt=0,N;
int main()
{
    cin>>N;
    for (Int i=1;i<=N;++i)
        cin>>arr[i];
    for (Int i=1;i<=N;++i)
    {
        if (arr[arr[i]]==i)
            ++cnt;
    }
    cout<<cnt/2;
    return 0;
}

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