Submission #890910

---

Source Code Expand

//satyaki3794
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define MOD (1000000007LL)
#define LEFT(n) (2*(n))
#define RIGHT(n) (2*(n)+1)
 
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
 
ll pwr(ll base, ll p, ll mod = MOD){
ll ans = 1;while(p){if(p&1)ans=(ans*base)%mod;base=(base*base)%mod;p/=2;}return ans;
}
 
ll gcd(ll a, ll b){
    if(b == 0)  return a;
    return gcd(b, a%b);
}


int n, arr[100005];


int main(){

    ios_base::sync_with_stdio(0);

    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>arr[i];

    int ans = 0;
    for(int i=1;i<=n;i++)
        if(arr[i] > i && arr[arr[i]] == i)
            ans++;

    cout<<ans;
    return 0;
}

Submission Info

Judge Result