poj 3335 Rotating Scoreboard

这是一道求凸多边形多核的问题；

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<queue>
#include<set>
#include<map>
#include<cstring>
#include<vector>
#include<string>
#define LL long long
using namespace std;
class Point
{
public:
      double x,y;    
};
Point point[124],p[124],q[124];
double A,B,C;
void Get_line( Point a, Point b )
{
    A = b.y - a.y;
    B = a.x - b.x;
    C = b.x*a.y-a.x*b.y;    
}
Point Get_Point( Point a, Point b )
{
    Point ans;
    double u = fabs( a.x*A + a.y*B + C );
    double v = fabs( b.x*A + b.y*B + C );
    ans.x = ( a.x*v + b.x*u )/( u + v );
    ans.y = ( a.y*v + b.y*u )/( u + v );
    return ans;     
}
int Cut_Area( int n )
{
    int m = 0;
    for( int i = 1 ;i <= n ; i ++ )
    {
         if( p[i].x*A + p[i].y*B + C >=0 )
             q[++m] = p[i];
         else
         {
             if( p[i+1].x*A + p[i+1].y*B + C >0 )
                 q[++m] = Get_Point( p[i] , p[i+1] );             
             if( p[i-1].x*A + p[i-1].y*B + C >0 )
                 q[++m] = Get_Point( p[i] , p[i-1] );
         }    
    }
    for( int i = 1; i <= m ; i ++ )
         p[i] = q[i];
    p[m+1] = q[1];
    p[0] = q[m];
    return m;    
}
bool Solve( int n )
{
     int m = n;
     point[n+1] = point[1];
     for( int i = 1 ; i <= n+1 ; i ++ )
          p[i] = point[i];
     p[0] = p[n];
     for( int i = 1 ; i <= n ; i ++ )
     {
          Get_line( point[i], point[i+1] );
          m = Cut_Area( m );        
     }    
     if( m ==0  ) return false;
     else return true;
}
int main(  )
{
    int T,n;
    while( scanf( "%d",&T )==1 )
    {
        while( T-- )
        {
            scanf( "%d",&n );
            for( int i = 1 ; i <= n ;  i ++ )
                 scanf( "%lf%lf",&point[i].x,&point[i].y );
            if(Solve( n )) puts( "YES" );
            else puts( "NO" );
        }    
    }
    //system( "pause" );
    return 0;
}