Submission #7117672
Source Code Expand
#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define dbg(...) do{cerr<<__LINE__<<": ";dbgprint(#__VA_ARGS__, __VA_ARGS__);}while(0);
using namespace std;
namespace std{template<class S,class T>struct hash<pair<S,T>>{size_t operator()(const pair<S,T>&p)const{return ((size_t)1e9+7)*hash<S>()(p.first)+hash<T>()(p.second);}};template<class T>struct hash<vector<T>>{size_t operator()(const vector<T> &v)const{size_t h=0;for(auto i : v)h=h*((size_t)1e9+7)+hash<T>()(i)+1;return h;}};}
template<class T>ostream& operator<<(ostream &os, const vector<T> &v){os<<"[ ";rep(i,v.size())os<<v[i]<<(i==v.size()-1?" ]":", ");return os;}template<class T>ostream& operator<<(ostream &os,const set<T> &v){os<<"{ "; for(const auto &i:v)os<<i<<", ";return os<<"}";}
template<class T,class U>ostream& operator<<(ostream &os,const map<T,U> &v){os<<"{";for(const auto &i:v)os<<" "<<i.first<<": "<<i.second<<",";return os<<"}";}template<class T,class U>ostream& operator<<(ostream &os,const pair<T,U> &p){return os<<"("<<p.first<<", "<<p.second<<")";}
void dbgprint(const string &fmt){cerr<<endl;}template<class H,class... T>void dbgprint(const string &fmt,const H &h,const T&... r){cerr<<fmt.substr(0,fmt.find(","))<<"= "<<h<<" ";dbgprint(fmt.substr(fmt.find(",")+1),r...);}
typedef long long ll;typedef vector<int> vi;typedef pair<int,int> pi;const int inf = (int)1e9;const double INF = 1e12, EPS = 1e-9;
int main(){
cin.tie(0); cin.sync_with_stdio(0);
int n, ans = 0; cin >> n;
vi to(n); rep(i, n) cin >> to[i], to[i]--;
rep(i, n) if(to[to[i]] == i) ans++;
cout << ans / 2 << endl;
return 0;
}
Submission Info
Submission Time |
|
Task |
B - Friendly Rabbits |
User |
nadeko |
Language |
C++14 (GCC 5.4.1) |
Score |
200 |
Code Size |
1683 Byte |
Status |
AC |
Exec Time |
9 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 |
9 ms |
640 KB |
1_02.txt |
AC |
9 ms |
640 KB |
1_03.txt |
AC |
9 ms |
640 KB |
1_04.txt |
AC |
9 ms |
640 KB |
1_05.txt |
AC |
9 ms |
640 KB |
1_06.txt |
AC |
9 ms |
640 KB |
1_07.txt |
AC |
9 ms |
640 KB |
1_08.txt |
AC |
4 ms |
384 KB |
1_09.txt |
AC |
8 ms |
640 KB |
1_10.txt |
AC |
7 ms |
512 KB |
1_11.txt |
AC |
3 ms |
384 KB |