Submission #891644


Source Code Expand

#include <bits/stdc++.h> // {{{
// clang-format off
#define ARG4(_1, _2, _3, _4, ...) _4
#define rep(...) ARG4(__VA_ARGS__, FOR, REP)(__VA_ARGS__)
#define REP(i, a) FOR(i, 0, a)
#define FOR(i, a, b) for (int i = (a); i < (int)(b); ++i)
#define rrep(...) ARG4(__VA_ARGS__, RFOR, RREP)(__VA_ARGS__)
#define RREP(i, a) RFOR(i, 0, a)
#define RFOR(i, a, b) for (int i = (b)-1; i >= (int)(a); --i)
#define ALL(c) (c).begin(), (c).end()
#define TEN(n) ((ll)(1e##n))
#define pb emplace_back
#define mp make_pair
#define fi first
#define se second
#define USE1(T) template <typename T> inline
#define USE2(T, U) template <typename T, typename U> inline
#define mygc(c) (c) = getchar_unlocked()
#define mypc(c) putchar_unlocked(c)

template <typename T> using duo = std::pair<T, T>;
template <typename T> using vec = std::vector<T>;
using ll = long long;
using pii = duo<int>;
USE2(T,U)bool chmax(T&x,U a){return x<a&&(x=a,1);}
USE2(T,U)bool chmin(T&x,U a){return a<x&&(x=a,1);}
USE1(T=int)T in(){T x;std::cin>>x;return x;}
USE1(T=int)vec<T>in(int n){vec<T>v;v.reserve(n);rep(i,n)v.pb(in<T>());return v;}
USE1(T)vec<std::pair<T,int>>zipi(const vec<T>&x,int s=0){int N=x.size();vec<std::pair<T,int>>v;v.reserve(N);rep(i,N)v.pb(x[i],s+i);return v;}
USE1(T)vec<T>ndvec(T v,int n){return vec<T>(n,v);}
USE2(T,...Ts)auto ndvec(T v,int n,Ts...ns)->vec<decltype(ndvec(v,ns...))>{return ndvec(ndvec(v,ns...),n);}
USE1(T)void pr(T x){std::cout<<x<<'\n';}
USE2(T,...Ts)void pr(T x,Ts...xs){std::cout<<x<<' ';pr(xs...);}
USE1(T=int)T rd(){T x=0,m=0,k;for(;;){mygc(k);if(k=='-'){m=1;break;}if('0'<=k&&k<='9'){x=k-'0';break;}}for(;;){mygc(k);if(k<'0'||'9'<k)break;x=x*10+k-'0';}return x;}
USE1(T=int)void wr(T x,char c='\n'){int s=0,m=0;char b[32];if(x<0)m=1,x=-x;for(;x;x/=10)b[s++]=x%10;if(!s)b[s++]=0;if(m)mypc('-');for(;s--;)mypc(b[s]+'0');mypc(c);}
// clang-format on
// }}}
struct IoSetup { // {{{
  IoSetup() {
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);
    std::cout.precision(10);
    std::cerr.precision(10);
  }
} iosetup; //}}}
using namespace std;
const int inf = 1001001001;
const ll infl = 1001001001001001001ll;
const int dd[] = {0, 1, 0, -1, 0};

signed main() { //
  int N = in();
  auto A = in(N);
  int cnt = 0;
  rep(i, N) {
    int j = A[i] - 1;
    if (i > j) continue;
    if (A[j] == i + 1) cnt++;
  }
  pr(cnt);

  return 0;
}

Submission Info

Submission Time
Task B - Friendly Rabbits
User orisano
Language C++14 (GCC 5.4.1)
Score 200
Code Size 2405 Byte
Status AC
Exec Time 11 ms
Memory 768 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 2 ms 256 KB
0_01.txt AC 2 ms 256 KB
0_02.txt AC 2 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 768 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 512 KB
1_11.txt AC 4 ms 384 KB