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 |
|
|
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 |