POJ-2318

/**
          题意：给一个区域的左上和右上坐标，然后给出区域中的n条边，然后，给出m个玩具的坐标；
                    求每个玩具都在那个区域
          做法：计算几何
**/
#include <iostream>
#include<cmath>
#include<algorithm>
#include<string.h>
#include<stdio.h>
#define maxn 5000 + 10
using namespace std;
int n,m;
int mmap[maxn];
const double eps = 1e-8;
const  double PI = acos(-1.0);
struct Point
{
    double x;
    double y;
    Point() {}
    Point(double _x,double _y)
    {
        x = _x;
        y = _y;
    }
    Point operator - (const Point &b) const
    {
        return Point(x - b.x,y - b.y);
    }
    double operator ^(const Point &b) const
    {
        return x*b.y - y*b.x;
    }
    double  operator *(const Point &b) const
    {
        return x*b.x + y*b.y;
    }
};
struct Line
{
    Point s;
    Point e;
    Line() {}
    Line(Point _s,Point _e)
    {
        s = _s;
        e = _e;
    }
} line[maxn];
int mul(Point a,Point b,Point c)
{
    return (b - a) ^(c - a);
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
#endif // ONLINE_JUDGE
    int x1,y1,x2,y2;
    while(~scanf("%d",&n))
    {
        if(n == 0) break;
        memset(mmap,0,sizeof(mmap));
        scanf("%d %d %d %d %d",&m,&x1,&y1,&x2,&y2);
        int u,l;
        for(int i=0; i<n; i++)
        {
            scanf("%d %d",&u,&l);
            line[i] = Line(Point(u,y1),Point(l,y2));
        }
        line[n] = Line(Point(x2,y1),Point(x2,y2));
        int x,y;
        for(int i=0; i<m; i++)
        {
            scanf("%d %d",&x,&y);
            Point pp = Point(x,y);
            int left = 0;
            int right = n;
            int tmp = 0;
            while(left <= right)
            {
                int mid = (left + right) >>1;
                if(mul(pp,line[mid].s,line[mid].e)<0)
                {
                    tmp = mid;
                    right = mid-1;
                }
                else left = mid+1;
            }
            mmap[tmp] ++;
        }
        for(int i=0; i<=n; i++)
        {
            printf("%d: %d\n",i,mmap[i]);
        }
        printf("\n");
    }
}