An Easy Physics Problem Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 1430    Accepted Submission(s): 270 Problem Description On an infinite smooth table, there's a big round fixed cylinder an…

HDU 5572 An Easy Physics Problem (计算几何) 题目链接http://acm.hdu.edu.cn/showproblem.php?pid=5572 Description On an infinite smooth table, there's a big round fixed cylinder and a little ball whose volume can be ignored. Currently the ball stands still at p…

2015上海区域赛现场赛第5题. 题目连接:http://acm.hdu.edu.cn/showproblem.php?pid=5572 题意:在平面上,已知圆(O, R),点B.A(均在圆外),向量V. 一个小球从A出发,沿速度向量V匀速前进,若撞到圆则发生弹性碰撞,沿“反射方向”继续匀速前进.问A点能否经过B点. 题目读懂了,把所有情况都考虑全,流程图就出来了,然后直接套模版即可(注意有些功能可剪裁~) 我的第一道计算几何,WA了一个星期啊...原因有姿势不对,精度不对,还有输出不对的. 不…

[题目概述] On an infinite smooth table, there's a big round fixed cylinder and a little ball whose volume can be ignored. Currently the ball stands still at point A, then we'll give it an initial speed and a direction. If the ball hits the cylinder, it w…

计算几何的题做的真是少之又少. 之前wa以为是精度问题,后来发现是情况没有考虑全... 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5572 题意: 给定起点A和方向V,路径中遇到圆柱体会发生折射,问能否到达终点B. 分析: 将路径表示为a+t∗v得到关于t的二元方程组,求出Δ. Δ小于等于0时,表示不会发生折射.直接判断ab是否共线. Δ大于0时,求出根. 根小于0说明路上不会发生折射,判断ab是否共线. 根大于等于0,仍然要判断ab是否共线…

An Easy Physics Problem Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 3845    Accepted Submission(s): 768 Problem Description On an infinite smooth table, there's a big round fixed cylinder an…

题目链接:HDU 5572 Problem Description On an infinite smooth table, there's a big round fixed cylinder and a little ball whose volume can be ignored. Currently the ball stands still at point \(A\), then we'll give it an initial speed and a direction. If t…

题意: 光滑平面,一个刚性小球,一个固定的刚性圆柱体 ,给定圆柱体圆心坐标,半径 ,小球起点坐标,起始运动方向(向量) ,终点坐标 ,问能否到达终点,小球运动中如果碰到圆柱体会反射. 学到了向量模板,写法简洁. #include<cstdio> #include<cstring> #include<algorithm> #include<iostream> #define clc(a,b) sizeof(a,b,sizeof(a)) #define LL l…

HDU 4974 A simple water problem pid=4974" target="_blank" style="">题目链接 签到题,非常easy贪心得到答案是(sum + 1) / 2和ai最大值的最大值 代码: #include <cstdio> #include <cstring> #include <algorithm> using namespace std; const int N =…

As Easy As A+B Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 53368    Accepted Submission(s): 22939 Problem Description These days, I am thinking about a question, how can I get a problem as…