Submission #891115
Source Code Expand
#include <iostream>
#include <queue>
#include <map>
#include <list>
#include <vector>
#include <string>
#include <stack>
#include <limits>
#include <cassert>
#include <fstream>
#include <cstring>
#include <cmath>
#include <bitset>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdio>
#include <ciso646>
#include <set>
#include <array>
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define inf 0x3f3f3f3f
#define INF INT_MAX/3
#define PB push_back
#define MP make_pair
#define ALL(a) (a).begin(),(a).end()
#define SET(a,c) memset(a,c,sizeof a)
#define CLR(a) memset(a,0,sizeof a)
#define pii pair<int,int>
#define pcc pair<char,char>
#define pic pair<int,char>
#define pci pair<char,int>
#define VS vector<string>
#define VI vector<int>
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define MIN(a,b) (a>b?b:a)
#define MAX(a,b) (a>b?a:b)
#define pi 2*acos(0.0)
#define INFILE() freopen("in0.txt","r",stdin)
#define OUTFILE()freopen("out0.txt","w",stdout)
#define ll long long
#define ull unsigned long long
#define eps 1e-14
#define FST first
#define SEC second
#define SETUP cin.tie(0), ios::sync_with_stdio(false), cout << setprecision(15)
namespace {
struct input_returnner {
int N; input_returnner(int N_ = 0) :N(N_) {}
template<typename T> operator vector<T>() const { vector<T> res(N); for (auto &a : res) cin >> a; return std::move(res); }
template<typename T> operator T() const { T res; cin >> res; return res; }
template<typename T> T operator - (T right) { return T(input_returnner()) - right; }
template<typename T> T operator + (T right) { return T(input_returnner()) + right; }
template<typename T> T operator * (T right) { return T(input_returnner()) * right; }
template<typename T> T operator / (T right) { return T(input_returnner()) / right; }
template<typename T> T operator << (T right) { return T(input_returnner()) << right; }
template<typename T> T operator >> (T right) { return T(input_returnner()) >> right; }
};
template<typename T> input_returnner in() { return in<T>(); }
input_returnner in() { return input_returnner(); }
input_returnner in(int N) { return std::move(input_returnner(N)); }
}
void solve();
/// ---template---
signed main(void) {
SETUP;
solve();
return 0;
}
struct Point {
int x;
int y;
Point(int x_, int y_):x(x_),y(y_){}
Point() {}
};
bool operator < (list<Point> left, list<Point> right) {
return left.size() < right.size();
}
int dx[] = {1,0,-1,0};
int dy[] = {0,-1,0,1};
void solve() {
int N = in();
vector<int> a = in(N);
ll cnt = 0;
REP(i, N) {
cnt += (a[a[i]-1] == i+1);
}
cout << cnt/2 << endl;
}
Submission Info
Submission Time |
|
Task |
B - Friendly Rabbits |
User |
kurenaif |
Language |
C++14 (GCC 5.4.1) |
Score |
200 |
Code Size |
2874 Byte |
Status |
AC |
Exec Time |
11 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 |
2 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 |
640 KB |
1_11.txt |
AC |
4 ms |
384 KB |