POJ 2318

 第一道计算几何。

二分一下用叉积来判。。看了DIS上说要INT64，就改INT64了。。。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int Max=5050;

struct e{
    int x1,x2;
}edge[Max];
struct c{
    int x,y;
}cal[4];

int n,m;
int X1,Y1,X2,Y2;
int ans[Max];
int u,v;

void init(){
    for(int i=0;i<=n;i++){
        ans[i]=0;
    }
}

bool in(){
    if(u>=X1&&u<=X2&&v>=Y2&&v<=Y1)
    return true;
    return false;
}

__int64 multi(int i){
    int j=i+1;
    if(j==4) j=0;
    return (__int64)(u-cal[i].x)*(__int64)(cal[j].y-cal[i].y)-(__int64)(v-cal[i].y)*(__int64)(cal[j].x-cal[i].x);
}

bool judge(int mid){
    __int64 pre,now;
    cal[0].x=edge[mid].x1; cal[0].y=Y1;
    cal[1].x=X2; cal[1].y=Y1;
    cal[2].x=X2; cal[2].y=Y2;
    cal[3].x=edge[mid].x2; cal[3].y=Y2;
    for(int i=0;i<4;i++){
        now=multi(i);
        if(i>0){
            if(pre*now<0)
            return false;
        }
        pre=now;
    }
    return true;
}

void slove(){
    int low=0,high=n;
    int anst;
    while(low<=high){
        int mid=(low+high)/2;
        if(judge(mid)){
            anst=mid; low=mid+1;
        }
        else high=mid-1;
    }
    ans[anst]++;
}

int main(){
    while(scanf("%d",&n)!=EOF){
        if(n==0) break;
        scanf("%d%d%d%d%d",&m,&X1,&Y1,&X2,&Y2);
        init();
        edge[0].x1=X1,edge[0].x2=X1;
        for(int i=1;i<=n;i++){
            scanf("%d%d",&edge[i].x1,&edge[i].x2);
        }
        for(int i=0;i<m;i++){
            scanf("%d%d",&u,&v);
            if(in())
                slove();
        }
        for(int i=0;i<=n;i++)
        printf("%d: %d
",i,ans[i]);
        printf("
");
    }
    return 0;
}