Submission #891665

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Source Code Expand

#include<bits/stdc++.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) for(int i = 0; i < (b); i++)
#define all(a) (a).begin(), (a).end()
#define debug(x) cout << "debug " << x << endl;
#define INF (1 << 29)
using namespace std;

int main(){
    int n, cnt = 0;
    map<int, int> mi;
    cin >> n;
    rep(i,n){
        int a = i + 1, b;
        cin >> b;
        if(a > b) swap(a, b);
        if(mi[a] == b) cnt++;
        mi[a] = b;
    }
    cout << cnt << endl;
}

Submission Info

Judge Result