Submission #890708
Source Code Expand
#include <bits/stdc++.h>
using namespace std;
#ifdef _WIN32
#define scanfll(x) scanf("%I64d", x)
#define printfll(x) printf("%I64d", x)
#else
#define scanfll(x) scanf("%lld", x)
#define printfll(x) printf("%lld", x)
#endif
#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
#define repi(i,a,b) for(long long i = (long long)(a); i < (long long)(b); i++)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define mt make_tuple
#define mp make_pair
template<class T1, class T2> bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
using ll = long long; using vll = vector<ll>; using vvll = vector<vll>;
using ld = long double; using vld = vector<ld>;
using vi = vector<int>; using vvi = vector<vi>;
vll conv(vi& v) { vll r(v.size()); rep(i, v.size()) r[i] = v[i]; return r; }
using P = pair<ll, ll>;
template <typename T, typename U> ostream &operator<<(ostream &o, const pair<T, U> &v) { o << "(" << v.first << ", " << v.second << ")"; return o; }
template<size_t...> struct seq{}; template<size_t N, size_t... Is> struct gen_seq : gen_seq<N-1, N-1, Is...>{}; template<size_t... Is> struct gen_seq<0, Is...> : seq<Is...>{};
template<class Ch, class Tr, class Tuple, size_t... Is>
void print_tuple(basic_ostream<Ch,Tr>& os, Tuple const& t, seq<Is...>){ using s = int[]; (void)s{0, (void(os << (Is == 0? "" : ", ") << get<Is>(t)), 0)...}; }
template<class Ch, class Tr, class... Args>
auto operator<<(basic_ostream<Ch, Tr>& os, tuple<Args...> const& t) -> basic_ostream<Ch, Tr>& { os << "("; print_tuple(os, t, gen_seq<sizeof...(Args)>()); return os << ")"; }
ostream &operator<<(ostream &o, const vvll &v) { rep(i, v.size()) { rep(j, v[i].size()) o << v[i][j] << " "; cout << endl; } return o; }
template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '['; rep(i, v.size()) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]"; return o; }
template <typename T> ostream &operator<<(ostream &o, const set<T> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]"; return o; }
template <typename T, typename U> ostream &operator<<(ostream &o, const map<T, U> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]"; return o; }
template <typename T, typename U> ostream &operator<<(ostream &o, const unordered_map<T, U> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it; o << "]"; return o; }
string bits_to_string(ll mask, ll n) { string s; rep(i, n) s += '0' + !!(mask & (1ll << i)); return s; }
#define ldout fixed << setprecision(40)
static const double EPS = 1e-14;
static const long long INF = 1e18;
static const long long mo = 1e9+7;
int main(void) {
cin.tie(0); ios::sync_with_stdio(false);
ll n; cin >> n;
vll a(n); rep(i, a.size()) { cin >> a[i]; a[i]--; }
ll ret= 0 ;
rep(i, n) {
if (a[a[i]] == i) {
ret++;
}
}
cout << ret / 2 << endl;
return 0;
}
Submission Info
Submission Time |
|
Task |
B - Friendly Rabbits |
User |
hamko |
Language |
C++14 (GCC 5.4.1) |
Score |
200 |
Code Size |
3213 Byte |
Status |
AC |
Exec Time |
11 ms |
Memory |
1024 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 |
3 ms |
256 KB |
0_01.txt |
AC |
2 ms |
256 KB |
0_02.txt |
AC |
3 ms |
256 KB |
1_00.txt |
AC |
2 ms |
256 KB |
1_01.txt |
AC |
11 ms |
1024 KB |
1_02.txt |
AC |
11 ms |
1024 KB |
1_03.txt |
AC |
11 ms |
1024 KB |
1_04.txt |
AC |
11 ms |
1024 KB |
1_05.txt |
AC |
11 ms |
1024 KB |
1_06.txt |
AC |
11 ms |
1024 KB |
1_07.txt |
AC |
11 ms |
1024 KB |
1_08.txt |
AC |
6 ms |
512 KB |
1_09.txt |
AC |
10 ms |
896 KB |
1_10.txt |
AC |
9 ms |
768 KB |
1_11.txt |
AC |
4 ms |
384 KB |