Submission #2142158


Source Code Expand

#include <bits/stdc++.h>
#define REP(i,a,b) for(int i=(a);i<(b);i++)
#define RREP(i,a,b) for(int i=(a);i>=(b);i--)
#define pq priority_queue
#define P pair<int,int>
#define P2 pair<int,P>
#define P3 pair<int,P2>
typedef long long ll; typedef long double ld;
using namespace std;
const int INF=1e9, MOD=1e9+7, around[]={0,1,1,-1,-1,0,-1,1,0,0};
const int vx[]={1,0,-1,0}, vy[]={0,1,0,-1};
const int sqrtN = 512;
const int logN = 32;
const ll LINF=1e18;
const ld PI=abs(acos(-1));

int main(){
	int n, a[100010]; cin >> n;
	REP(i, 0, n) cin >> a[i], a[i]--;
	
	int c = 0;
	REP(i, 0, n) if(i == a[a[i]]) c++;
	cout << c / 2 << endl;
	return 0;
}

Submission Info

Submission Time
Task B - Friendly Rabbits
User ecasdqina
Language C++14 (GCC 5.4.1)
Score 200
Code Size 668 Byte
Status AC
Exec Time 36 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 1 ms 256 KB
0_01.txt AC 1 ms 256 KB
0_02.txt AC 1 ms 256 KB
1_00.txt AC 1 ms 256 KB
1_01.txt AC 36 ms 640 KB
1_02.txt AC 36 ms 640 KB
1_03.txt AC 36 ms 640 KB
1_04.txt AC 36 ms 640 KB
1_05.txt AC 36 ms 640 KB
1_06.txt AC 36 ms 640 KB
1_07.txt AC 36 ms 640 KB
1_08.txt AC 15 ms 384 KB
1_09.txt AC 29 ms 512 KB
1_10.txt AC 25 ms 512 KB
1_11.txt AC 6 ms 256 KB