Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 15060   Accepted: 7270 Description Calculate the number of toys that land in each bin of a partitioned toy box. Mom and dad have a problem - their child John never puts his toys away when h…

题目大意:给你一个矩形的左上角和右下角的坐标,然后这个矩形有 N 个隔板分割成 N+1 个区域,下面有 M 组坐标,求出来每个区域包含的坐标数.   分析:做的第一道计算几何题目....使用叉积判断方向,然后使用二分查询找到点所在的区域.   代码如下: ==========================================================================================================================…

题目传送门:POJ 2318 TOYS Description Calculate the number of toys that land in each bin of a partitioned toy box. Mom and dad have a problem - their child John never puts his toys away when he is finished playing with them. They gave John a rectangular bo…

题目传送门 题意:POJ 2318 有一个长方形,用线段划分若干区域,给若干个点,问每个区域点的分布情况 分析:点和线段的位置判断可以用叉积判断.给的线段是排好序的,但是点是无序的,所以可以用二分优化.用到了叉积 /************************************************ * Author :Running_Time * Created Time :2015/10/23 星期五 11:38:18 * File Name :POJ_2318.cpp ****…

POJ 2318: 题目大意:给定一个盒子的左上角和右下角坐标,然后给n条线,可以将盒子分成n+1个部分,再给m个点,问每个区域内有多少各点 这个题用到关键的一步就是向量的叉积,假设一个点m在 由abcd围成的四边形区域内,那么向量ab, bc, cd, da和点的关系就是,点都在他们的同一侧,我是按照逆时针来算的,所以只需要判断叉积是否小于0就行了.还有一个问题就是这个题要求时间是2s,所以直接找,不用二分也能过,不过超过1s了,最好还是二分来做,二分时间170ms,二分的时候要把最左边的一条…

链接:poj 2318 题意:有一个矩形盒子,盒子里有一些木块线段.而且这些线段坐标是依照顺序给出的. 有n条线段,把盒子分层了n+1个区域,然后有m个玩具.这m个玩具的坐标是已知的,问最后每一个区域有多少个玩具 分析:从左往右.直到推断玩具是否在线段的逆时针方向为止.这个就须要用到叉积,当然能够用二分查找优化. 叉积:已知向量a(x1,y1),向量b(x2,y2),axb=x1*y2-x2*y1, 若axb>0,a在b的逆时针方向,若axb<0,则a在b的顺时针方向 注:每组数据后要多空一行…

TOYS Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 13262   Accepted: 6412 Description Calculate the number of toys that land in each bin of a partitioned toy box. Mom and dad have a problem - their child John never puts his toys away w…

2318 2398 题意:给出n条线将一块区域分成n+1块空间,再给出m个点,询问这些点在哪个空间里. 思路:由于只要求相对位置关系,而对具体位置不关心,那么易使用叉积性质得到相对位置关系(左侧/右侧),再因为是简单几何线段不相较,即有序分布,那么在求在哪个区间时可以先对所有线段根据x坐标排序,使用二分减少复杂度. /** @Date : 2017-07-11 11:05:59 * @FileName: POJ 2318 叉积性质.cpp * @Platform: Windows * @Auth…

TOYS Time Limit: 2000MS Memory Limit: 65536K Description Calculate the number of toys that land in each bin of a partitioned toy box. Mom and dad have a problem - their child John never puts his toys away when he is finished playing with them. They g…

Calculate the number of toys that land in each bin of a partitioned toy box. 计算每一个玩具箱里面玩具的数量 Mom and dad have a problem - their child John never puts his toys away when he is finished playing with them. They gave John a rectangular box to put his toy…