Submission #2130108

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Source Code Expand

#include"bits/stdc++.h"


#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fr(x) freopen(x,"r",stdin)
#define fw(x) freopen(x,"w",stdout)
#define iout(x) printf("%d\n",x)
#define lout(x) printf("%lld\n",x)
#define REP(x,l,u) for(int x = (l);x<=(u);x++)
#define RREP(x,l,u) for(int x = (l);x>=(u);x--)
#define mst(x,a) memset(x,a,sizeof(x))
#define PII pair<int,int>
#define PLL pair<ll,ll>
#define MP make_pair
#define se second
#define fi first
#define dbg(x) cout<<#x<<" = "<<(x)<<endl;
#define sz(x) ((int)x.size())
#define cl(x) x.clear()

typedef  long long ll;
typedef unsigned long long ull;
typedef double db;
typedef double ld;
using namespace std;

const int maxn = 200010;
const int mod = 1e9+7;
const int MAX = 1000000010;
const double eps = 1e-6;
const double PI = acos(-1);

template<typename T> inline void read(T &x){
x=0;T f=1;char ch;do{ch=getchar();if(ch=='-')f=-1;}while(ch<'0'||ch>'9');do x=x*10+ch-'0',ch=getchar();while(ch<='9'&&ch>='0');x*=f;
}

template<typename A,typename B> inline void read(A&x,B&y){read(x);read(y);}
template<typename A,typename B,typename C> inline void read(A&x,B&y,C&z){read(x);read(y);read(z);}
template<typename A,typename B,typename C,typename D> inline void read(A&x,B&y,C&z,D&w){read(x);read(y);read(z);read(w);}
template<typename A,typename B> inline A fexp(A x,B p){A ans=1;for(;p;p>>=1,x=1LL*x*x%mod)if(p&1)ans=1LL*ans*x%mod;return ans;}
template<typename A,typename B> inline A fexp(A x,B p,A mo){A ans=1;for(;p;p>>=1,x=1LL*x*x%mo)if(p&1)ans=1LL*ans*x%mo;return ans;}

int n;

int x[maxn],y[maxn];

ld fix(ld x){
	if(x<0)x+=PI*2;
	if(x>PI*2)x-=PI*2;
	return x;
}

int vi[maxn];

ld hs[maxn];int cnt;

void Work(){
	REP(i,1,n){
		cnt=0;
		REP(j,1,n)if(i!=j){
			ld _x=fix(atan2(y[j]-y[i],x[j]-x[i]));
			_x=fix(_x+PI/2);
			ld y=fix(_x+PI);
			hs[++cnt]=_x;hs[++cnt]=y;
		}
		sort(hs+1,hs+cnt+1);cnt=unique(hs+1,hs+cnt+1)-hs-1;
		REP(j,1,cnt)vi[j]=0;
//		REP(j,1,cnt)cout<<hs[j]<<' ';cout<<endl;
		REP(j,1,n)if(i!=j){
			ld _x=fix(atan2(y[j]-y[i],x[j]-x[i]));
			_x=fix(_x+PI/2);
			ld y=fix(_x+PI);
			int xx=LB(hs+1,hs+cnt+1,_x)-hs;
			int yy=LB(hs+1,hs+cnt+1,y)-hs;
			while(xx!=yy){
				vi[xx]=1;
				xx++;if(xx>cnt)xx=1;
			}
		}
		double ans=0;
		REP(j,1,cnt)if(!vi[j])if(j==cnt)ans+=fix(hs[1]-hs[j]);else ans+=fix(hs[j+1]-hs[j]);
		printf("%.15lf\n",ans/PI/2);
	}
}

void Init(){
	read(n);
	REP(i,1,n)read(x[i],y[i]);
}

int main(){
	Init();
	Work();
	return 0;
}

Submission Info

Judge Result