POJ 2318 TOYS

#include<stdio.h>
#include<string.h>
#define Max 5010
struct node
{
int x,y;
}low[Max],high[Max];
node a,b;
int n,m;
int cal(node aa,node bb,node cc)
{
//return (cc.x-aa.x)*(bb.y-aa.y)-(cc.y-aa.y)*(bb.x-aa.x);//第一种
return (bb.x-cc.x)*(aa.y-cc.y)-(bb.y-cc.y)*(aa.x-cc.x);//第二种
}
int solve(node cc)
{
int l,r,mid;
l=0;r=n-1;
while(l<=r)
{
mid=(l+r)>>1;
if(cal(low[mid],high[mid],cc)>0)
l=mid+1;
else r=mid-1;
}
return l;
}
int num[Max];
int main()
{
int i;
while(scanf("%d",&n)!=EOF&&n!=0)
{
scanf("%d%d%d%d%d",&m,&a.x,&a.y,&b.x,&b.y);
for(i=0;i<n;i++)
{
scanf("%d %d",&high[i].x,&low[i].x);
high[i].y=a.y;
low[i].y=b.y;

}
low[n].x=b.x;
low[n].y=b.y;
high[n].x=a.x;
high[n].y=a.y;
node temp;
memset(num,0,sizeof(num));
while(m--)
{
scanf("%d %d",&temp.x,&temp.y);
int pos=solve(temp);
num[pos]++;
}
for(i=0;i<=n;i++)
printf("%d: %d\n",i,num[i]);
printf("\n");
}

return 0;
}