Submission #2210201

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Source Code Expand

#include<bits/stdc++.h>
#define fi first
#define se second
#define show(x) cerr<<#x<<"="<<x<<"\n"
typedef long long ll;
template<typename T>
void print_to(std::ostream &os,const char *,const char *tail,const T &fst){
  os<<fst<<tail;
}
template<typename Fst,typename... Rst>
void print_to(std::ostream &os,const char *del,const char *tail,const Fst &fst,const Rst &... rst){
  os<<fst<<del;
  print_to(os,del,tail,rst...);
}
template<typename Iter>
void print_to_(std::ostream &os,const char *del,const char *tail,Iter bgn,Iter end){
  for(Iter it=bgn;it!=end;){
    os<<*it;
    if(++it!=end)os<<del;
    else os<<tail;
  }
}
template<typename Fst,typename... Rst>
void println(const Fst &fst,const Rst &... rst){
  print_to(std::cout,"\n","\n",fst,rst...);
}
template<typename Fst,typename... Rst>
void print(const Fst &fst,const Rst &... rst){
  print_to(std::cout," ","\n",fst,rst...);
}
template<typename Iter>
void println_(Iter bgn,Iter end){
  print_to_(std::cout," ","\n",bgn,end);
}
using namespace std;
//const ll MOD=(ll)1e9+7;
//const ll inf=(ll)1e14;
const double PI=acos(-1.0);
const double EPS=1e-10;
const int dy[]={1,0,-1};
const int dx[]={1,0,-1};
int n,m,h,w;
string s;
ll x[2001],y[2001];

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.precision(10);
  cout<<fixed;
#ifdef LOCAL_DEFINE
  FILE *stream1;
  //FILE *stream2;
  stream1=freopen("in","r",stdin);
  //stream2=freopen("out","w",stdout);
  if(stream1==NULL)return 0;
  //if(stream2==NULL)return 0;
#endif
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>x[i]>>y[i];
  }
  ll ans1=0,ans2=0,ans3=0;
  for(int i=0;i<n;i++){
    vector<double> v;
    for(int j=0;j<n;j++){
      if(i==j)continue;
      v.push_back(atan2(y[j]-y[i],x[j]-x[i]));
    }
    sort(v.begin(),v.end());
    for(int j=0;j<n-1;j++){
      v.push_back(v[j]+2*PI);
    }
    for(int j=0;j<n-1;j++){
      int a=lower_bound(v.begin(),v.end(),v[j]+PI/2-EPS)-v.begin();
      int b=upper_bound(v.begin(),v.end(),v[j]+PI/2+EPS)-v.begin();
      int c=lower_bound(v.begin(),v.end(),v[j]+PI)-v.begin();
      ans2+=b-a;
      ans3+=c-b;
    }
  }
  ans1=(ll)n*(n-1)*(n-2)/6-ans2-ans3;
  print(ans1,ans2,ans3);
#ifdef LOCAL_DEFINE
  cerr<<"Time elapsed: "<<1.0*clock()/CLOCKS_PER_SEC<<"s.\n";
  fclose(stream1);
  //fclose(stream2);
#endif
  return 0;
}

Submission Info

Judge Result