POJ 2318 TOYS

#include<stdio.h>
#include<string.h>
#define fab(a)(a<1e-6)?-1:1
const int MAXN=5002;
typedef struct
{
    __int64 x,_x,y,_y;
}Point;
Point p[MAXN];
double det(double x1,double y1,double x2,double y2)
{
    return x1*y2-x2*y1;
}
double cross(__int64 x,__int64 y,Point loc)
{
    return fab(det(loc.x*1.0-x*1.0,loc.y*1.0-y*1.0,loc._x*1.0-x*1.0,loc._y*1.0-y*1.0));
}
int fun(__int64 x,__int64 y,__int64 front,__int64 rear)
{
    int mid;
    do
    {
        mid=front+(rear-front)/2;
        int ans1=cross(x,y,p[mid]);
        int ans2=cross(x,y,p[mid+1]);
        if(ans1*ans2<0)return mid;
        else if(ans1>0)front=mid;
        else rear=mid;
    }while(1);
}
int main()
{
    __int64 n,m,i,num[MAXN];
    __int64 a,b,X,Y,_X,_Y;
    while(scanf("%I64d",&n),n)
    {
        memset(num,0,sizeof(num));
        scanf("%I64d%I64d%I64d%I64d%I64d",&m,&X,&Y,&_X,&_Y);
        p[0].x=p[0]._x=X;
        p[0].y=p[n+1].y=Y;
        p[0]._y=p[n+1]._y=_Y;
        p[n+1].x=p[n+1]._x=_X;
        for(i=1;i<=n;i++)
        {
            scanf("%I64d%I64d",&X,&_X);
            p[i].x=X;
            p[i].y=Y;
            p[i]._x=_X;
            p[i]._y=_Y;
        }
        for(i=0;i<m;i++)
        {
            scanf("%I64d%I64d",&a,&b);
            num[(fun(a,b,0,n+1))]++;
        }
        for(i=0;i<=n;i++)
          printf("%I64d: %I64d\n",i,num[i]);
        printf("\n");
    }
    return 0;
}