poj2318

/***************************************************************\
 *Author:Hu Wenbiao
 *Created Time: Tue 27 Jul 2010 07:10:34 PM CST
 *File Name: main.cpp
 *Description:几何题目。简单的叉积应用
\***************************************************************/
//*========================*Head File*========================*\\

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
/*----------------------*Global Variable*----------------------*/
struct Cardboard{//隔板
 int u,l;
}card[5010];
int toynum[5010],n,m,x1,y1,x2,y2,X,Y;//toynum计算数目
//*=======================*Main Program*=======================*//
using namespace std;

bool left(int m){//判断toy在第m个隔板左边
 int a=card[m].u-card[m].l,b=y1-y2,c=X-card[m].l,d=Y-y2;
 return a*d-b*c>0;
}

void location(){//二分法,将toy所在的区间数目加1
 int s=0,t=n;
 int m=(s+t)/2;
 while(s<t){
  if(left(m)){
   t=m;
   m=(s+t)/2;
  }
  else{
   s=m+1;
   m=(s+t)/2;
  }
 }
 toynum[t]++;
}
int main(){
 //freopen("input","r",stdin);
 while(scanf("%d%d%d%d%d%d",&n,&m,&x1,&y1,&x2,&y2)!=EOF&&n){
  for(int i=0;i<n;i++)
    scanf("%d%d",&card[i].u,&card[i].l);
  card[n].u=card[n].l=x2;//用box右边界作第n个区间的‘隔板’
  memset(toynum,0,sizeof(toynum));
  while(m--){
   scanf("%d%d",&X,&Y);
   location();
  }
  for(int i=0;i<=n;i++)
    printf("%d: %d\n",i,toynum[i]);
  printf("\n");
 }
}

原文地址:https://www.cnblogs.com/Open_Source/p/1904905.html