Submission #890835

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int N; cin >> N;

    auto friends = vector<int>(N);
    for (auto& x : friends)
    {
        cin >> x;
        x--;
    }

    auto result = 0;
    for (auto i = 0; i < N; i++)
    {
        const auto j = friends[i];
        if (friends[j] == i && i <= j)
            result++;
    }

    cout << result << endl;
}

Submission Info

Judge Result