Submission #890977
Source Code Expand
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()
#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))
// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD
// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;
int n;
int a[125252];
set<int> b[125252];
int main(){
scanf("%d",&n);
REP(i,n)scanf("%d",a+i),--a[i];
REP(i,n)b[a[i]].insert(i);
int ans = 0;
REP(i,n)if(b[i].count(a[i]))++ans;
ans/=2;
cout<<ans<<endl;
return 0;
}
Submission Info
Submission Time
2016-09-24 21:03:37+0900
Task
B - Friendly Rabbits
User
rickytheta
Language
C++14 (GCC 5.4.1)
Score
200
Code Size
1114 Byte
Status
AC
Exec Time
36 ms
Memory
11136 KB
Compile Error
./Main.cpp: In function ‘int main()’:
./Main.cpp:39:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d",&n);
^
./Main.cpp:40:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
REP(i,n)scanf("%d",a+i),--a[i];
^
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
9 ms
6144 KB
0_01.txt
AC
9 ms
6144 KB
0_02.txt
AC
9 ms
6144 KB
1_00.txt
AC
9 ms
6144 KB
1_01.txt
AC
33 ms
11136 KB
1_02.txt
AC
34 ms
11136 KB
1_03.txt
AC
34 ms
11136 KB
1_04.txt
AC
35 ms
11136 KB
1_05.txt
AC
35 ms
11136 KB
1_06.txt
AC
35 ms
11136 KB
1_07.txt
AC
36 ms
11136 KB
1_08.txt
AC
18 ms
8064 KB
1_09.txt
AC
31 ms
10240 KB
1_10.txt
AC
26 ms
9600 KB
1_11.txt
AC
13 ms
6912 KB