Submission #890904


Source Code Expand

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
//#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
//#include<list>
#include<queue>
#include<deque>
#include<algorithm>
//#include<numeric>
#include<utility>
//#include<memory>
#include<functional>
#include<cassert>
#include<set>
#include<stack>
#include<random>

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, -1, 0, 1};
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int, int> pii;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    cin >> N;
    vector<int> A(N);
    for (int i = 0; i < N; i++) {
        cin >> A[i];
        A[i]--;
    }
    int ans = 0;
    for (int i = 0; i < N; i++) {
        if (A[A[i]] == i) ans++;
    }
    assert(ans%2 == 0);
    cout << ans/2 << endl;
    return 0;
}

Submission Info

Submission Time
Task B - Friendly Rabbits
User mayoko
Language C++14 (GCC 5.4.1)
Score 200
Code Size 995 Byte
Status AC
Exec Time 11 ms
Memory 640 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 200 / 200
Status
AC × 3
AC × 15
Set Name Test Cases
Sample 0_00.txt, 0_01.txt, 0_02.txt
All 0_00.txt, 0_01.txt, 0_02.txt, 1_00.txt, 1_01.txt, 1_02.txt, 1_03.txt, 1_04.txt, 1_05.txt, 1_06.txt, 1_07.txt, 1_08.txt, 1_09.txt, 1_10.txt, 1_11.txt
Case Name Status Exec Time Memory
0_00.txt AC 3 ms 256 KB
0_01.txt AC 3 ms 256 KB
0_02.txt AC 3 ms 256 KB
1_00.txt AC 3 ms 256 KB
1_01.txt AC 11 ms 640 KB
1_02.txt AC 11 ms 640 KB
1_03.txt AC 11 ms 640 KB
1_04.txt AC 11 ms 640 KB
1_05.txt AC 11 ms 640 KB
1_06.txt AC 11 ms 640 KB
1_07.txt AC 11 ms 640 KB
1_08.txt AC 6 ms 384 KB
1_09.txt AC 9 ms 640 KB
1_10.txt AC 8 ms 512 KB
1_11.txt AC 4 ms 384 KB