Description The GX Light Pipeline Company started to prepare bent pipes for the new transgalactic light pipeline. During the design phase of the new pipe shape the company ran into the problem of determining how far the light can reach inside each co…

题目:http://poj.org/problem?id=1039 题意:有一宽度为1的折线管道,上面顶点为(xi,yi),所对应的下面顶点为(xi,yi-1),假设管道都是不透明的,不反射的,光线从左边入口处的(x1,y1),(x1,y1-1)之间射入,向四面八方传播,求解光线最远能传播到哪里(取x坐标)或者是否能穿透整个管道. 思路:最优的是 光线过一个上顶点,一个下顶点. #include<iostream> #include<cstdio> #include<cstr…

http://poj.org/problem?id=1039 题意 有一宽度为1的折线管道,上面顶点为(xi,yi),所对应的下面顶点为(xi,yi-1),假设管道都是不透明的,不反射的,光线从左边入口处的(x1,y1),(x1,y1-1)之间射入,向四面八方传播,求解光线最远能传播到哪里(取x坐标)或者是否能穿透整个管道. 分析 最远的直线必定经过一个上折点和一个下折点.枚举这两个点即可. #include <iostream> #include <stdio.h> #inclu…

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…

1039 -- Pipe 理解错题意一个晚上._(:з」∠)_ 题意很容易看懂,就是要求你求出从外面射进一根管子的射线,最远可以射到哪里. 正解的做法是,选择上点和下点各一个,然后对于每个折点位置竖直位置判断经过的点是否在管中.如果是,就继续找,如果不在管中,这时射线必然已经穿过管出去了,这时就要找射线和管上下壁的交点. 代码如下: #include <cstdio> #include <iostream> #include <algorithm> #include &…

http://acm.nyist.net/JudgeOnline/problem.php?pid=142 第一道解析几何问题,比较纠结,主要是几个解析几何的基本操作,包括求两线段的叉积,判断左右方向,判断是否相交, 计算交点等等,主要的思路就是穷举所有的折点的组合,取任意两个折点组成一条线,看看能不能跟所有的管道的上下折点构成的线段相交,如果所有都相交则说明光线能通过,否则求出所有光线中照的最远的那个(穷举的过程中设置一个记录变量) 这里就需要计算两个线段的交点(如果不能穿过管道,就要计算管道壁…

题目传送门 题意:一根管道,有光源从入口发射,问光源最远到达的地方. 分析:黑书上的例题,解法是枚举任意的一个上顶点和一个下顶点(优化后),组成直线,如果直线与所有竖直线段有交点,则表示能穿过管道. /************************************************ * Author :Running_Time * Created Time :2015/10/31 星期六 10:28:12 * File Name :POJ_1039.cpp ***********…

Description From the article Number Theory in the 1994 Microsoft Encarta: ``If a, b, c are integers such that a = bc, a is called a multiple of b or of c, and b or c is called a divisor or factor of a. If c is not 1/-1, b is called a proper divisor o…

Description Little Johnny has got a new car. He decided to drive around the town to visit his friends. Johnny wanted to visit all his friends, but there was many of them. In each street he had one friend. He started thinking how to make his trip as s…

Description You, as a member of a development team for a new spell checking program, are to write a module that will check the correctness of given words using a known dictionary of all correct words in all their forms. If the word is absent in the d…