http://poj.org/problem?id=3304 Segments Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9449   Accepted: 2902 Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that a…

// 判断线段和直线相交 POJ 3304 // 思路: // 如果存在一条直线和所有线段相交,那么平移该直线一定可以经过线段上任意两个点,并且和所有线段相交. #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> #include <map> #include <set> #include <queue> #includ…

题目链接:POJ 3304 Problem Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that after projecting these segments on it, all projected segments have at least one point in common. Input…

链接: http://poj.org/problem?id=1039 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=22013#problem/B Pipe Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 8350   Accepted: 2501 Description The GX Light Pipeline Company started to prep…

POJ 3304  Segments 题意:给定n(n<=100)条线段,问你是否存在这样的一条直线,使得所有线段投影下去后,至少都有一个交点. 思路:对于投影在所求直线上面的相交阴影,我们可以在那里作一条线,那么这条线就和所有线段都至少有一个交点,所以如果有一条直线和所有线段都有交点的话,那么就一定有解. 怎么确定有没直线和所有线段都相交?怎么枚举这样的直线?思路就是固定两个点,这两个点在所有线段上任意取就可以,然后以这两个点作为直线,去判断其他线段即可.为什么呢?因为如果有直线和所有线段都相…

题目链接 题意 : 能否找出一条直线使得所有给定的线段在该直线上的投影有一个公共点. 思路 : 假设存在一条直线a使得所有线段在该直线上的投影有公共点,则必存在一条垂直于直线a的直线b,直线b与所有线段相交,所以问题又转变为是否存在一条直线与所在所有线段相交. 假设这样的直线存在,则这一条直线可能与某一条或者某些线段的端点重合,也可能不重合.对于那些没有在端点相交的线段,我们可以把这一条直线通过旋转或平移,让其先与一条线段在线段的端点相交(那此时这一条直线与别的线段就在别的线段的中间相交), 然…

Segments Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7739   Accepted: 2316 Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that after projecting these segments…

Segments Time Limit: 1000MS   Memory Limit: 65536K       Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that after projecting these segments on it, all projected segments have…

Intersecting Lines Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 8637   Accepted: 3915 Description We all know that a pair of distinct points on a plane defines a line and that a pair of lines on a plane will intersect in one of three…

Segments Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 14178   Accepted: 4521 Description Given n segments in the two dimensional space, write a program, which determines if there exists a line such that after projecting these segments…