链接: http://poj.org/problem?id=1584 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=22013#problem/D A Round Peg in a Ground Hole Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 4475   Accepted: 1374 Description The DIY Furniture com…

首先判断是不是凸多边形 然后判断圆是否在凸多边形内 不知道给出的点是顺时针还是逆时针,所以用判断是否在多边形内的模板,不用是否在凸多边形内的模板 POJ 1584 A Round Peg in a Ground Hole(判断凸多边形,点到线段距离,点在多边形内) #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath&g…

链接: http://poj.org/problem?id=1584 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=22013#problem/D A Round Peg in a Ground Hole Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 4475   Accepted: 1374 Description The DIY Furniture com…

A Round Peg in a Ground Hole Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 4438   Accepted: 1362 Description The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to on…

A Round Peg in a Ground Hole Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 5456   Accepted: 1735 Description The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to on…

A Round Peg in a Ground Hole Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 6682   Accepted: 2141 Description The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to on…

http://poj.org/problem?id=1584 题意 按照顺时针或逆时针方向输入一个n边形的顶点坐标集,先判断这个n边形是否为凸包. 再给定一个圆形(圆心坐标和半径),判断这个圆是否完全在n边形内部. 分析 1.判断给出了多边形是不是凸多边形. 2.判断圆包含在凸多边形中:一定要保证圆心在凸多边形里面.然后判断圆心到每条线段的距离要大于等于半径.. #include <iostream> #include <stdio.h> #include <string.h…

题意: 给一个圆和一个多边形,多边形点可能按顺时针给出,也可能按逆时针给出,先判断多边形是否为凸包,再判断圆是否在凸包内. 解法: 先判是否为凸包,沿着i=0~n,先得出初始方向dir,dir=1为逆时针,dir=-1为顺时针,然后如果后面有两个相邻的边叉积后得出旋转方向为nowdir,如果dir*nowdir < 0,说明方向逆转了,即出现了凹点,说明不是凸多边形. 然后判圆是否在多边形内: 先判圆心是否在多边形内,用环顾法,然后如果在之内,则依次判断圆心与每条凸包边的距离与半径的距离,如果所…

题目传送门 题意:判断给定的多边形是否为凸的,peg(pig?)是否在多边形内,且以其为圆心的圆不超出多边形(擦着边也不行). 分析:判断凸多边形就用凸包,看看点集的个数是否为n.在多边形内用叉积方向来判断,最后再用点到直线的距离和半径比大小(不是线段) /************************************************ * Author :Running_Time * Created Time :2015/11/2 星期一 19:49:13 * File Nam…

先判断是不是N多边形,求一下凸包,如果所有点都用上了,那么就是凸多边形 判断圆是否在多边形内, 先排除圆心在多边形外的情况 剩下的情况可以利用圆心到每条边的最短距离与半径的大小来判断 #include<cstdio> #include<cstring> #include<vector> #include<cmath> #include<queue> #include<list> #include<algorithm> us…

A Round Peg in a Ground Hole Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 5684 Accepted: 1827 Description The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to one an…

A Round Peg in a Ground Hole Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 5741   Accepted: 1842 Description The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to on…

Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 4628   Accepted: 1434 Description The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to one another using a wooden peg…

含[判断凸包],[判断点在多边形内],[判断圆在多边形内]模板  凸包:即凸多边形 用不严谨的话来讲,给定二维平面上的点集,凸包就是将最外层的点连接起来构成的凸多边形,它能包含点集中所有的点. The DIY Furniture company specializes in assemble-it-yourself furniture kits. Typically, the pieces of wood are attached to one another using a wooden pe…

http://poj.org/problem?id=1584 #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> using namespace std; ; const double pi=acos(-1.0); ; int cmp(double x) { ; ) ; ; } double sqr(double x) { return x*x; } struct po…

题目大意:首先给一个圆的半径和圆心,然后给一个多边形的所有点(多边形按照顺时针或者逆时针给的),求,这个多边形是否是凸多边形,如果是凸多边形在判断这个圆是否在这个凸多边形内.   分析:判断凸多边形可以使用相邻的三个点叉积判断,因为不知道顺时针还是逆时针,所以叉积如果有有整数和负数,那么一定不是凸多边形(注意允许多多点在一条线段上).判断圆在凸多边形首先要判断圆心是否在多边形内,如果在多边形内,再次判断圆心到达到变形每条边的最短距离,如果小于半径就是不合法.ps:一道好题,通过这个题学会了不少东…

http://poj.org/problem?id=1584 题意:判断所给的点能不能形成凸包,并判断所给的圆是否在凸包内. 改了好几天的一个题,今天才发现是输入顺序弄错了,办过的最脑残的事情..sad #include <stdio.h> #include <algorithm> #include <iostream> #include <string.h> #include <math.h> using namespace std; ; ;…

链接 题意甚是难懂!这是第二遍做这道题了,依旧无法理解题意,搜了下题意... 首先需要判断是不是为凸多边形.(从一个顶点走一遍即可,要注意顺逆时针,题目中没有指明) 其次看一下圆是不是能够放入多边形内.(首先判断一下圆心是否在圆内,然后枚举圆心到所有边的距离与半径r进行比较) #include <iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<stdli…

大致思路:首先对于所给的洞的点,判断是否是凸多边形,图形的输入和输出可以是顺时针或者逆时针,而且允许多点共线 Debug 了好几个小时,发现如下问题 判断三点是否共线,可用斜率公式判断 POINT point_A, point_B, point_C; if(point_A.x == point_B.x || point_B.x == point_C.x){ if(point_A.x == point_B.x && point_B.x == point_C.x) continue; }els…

POJ1584 题意:给定n条边首尾相连对应的n个点 判断构成的图形是不是凸多边形 然后给一个圆 判断圆是否完全在凸包内(相切也算) 思路:首先运用叉积判断凸多边形 相邻三条边叉积符号相异则必有凹陷 O(n) 之后首先判断圆心是否在凸多边形内 如果凸多边形的点有序 则可以在logn时间内判断 否则先排序再判断 O(nlogn) 然后用每条边(线段)判断到圆心的距离即可 这道题也没给数据范围 O(nlogn)是可以AC的. #include<iostream> #include<stdio…

POJ 3252:Round Numbers Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 10099 Accepted: 3669 Description The cows, as you know, have no fingers or thumbs and thus are unable to play Scissors, Paper, Stone' (also known as 'Rock, Paper, Sciss…

The cows, as you know, have no fingers or thumbs and thus are unable to play Scissors, Paper, Stone' (also known as 'Rock, Paper, Scissors', 'Ro, Sham, Bo', and a host of other names) in order to make arbitrary decisions such as who gets to be milked…

C. Ancient Berland Circus 题目连接: http://www.codeforces.com/contest/1/problem/C Description Nowadays all circuses in Berland have a round arena with diameter 13 meters, but in the past things were different. In Ancient Berland arenas in circuses were s…

You are a member of the space station engineering team, and are assigned a task in the construction process of the station. You are expected to write a computer program to complete the task. The space station is made up with a number of units, called…

题意:给定点A[0~n-1]和B[0],B[1],A[0].A[1]映射到B[0].B[1],求出其余点的映射B[2]~B[n-1]. 析:运用复数类,关键是用模板复数类,一直编译不过,我明明能编译过,交上就不过,只能写一个复数了... 代码如下: #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include…

传送门 题意:在平面中,有一个圆,有一个点,问能在这个圆中围出最大的圆的圆心坐标和半径.要求这个最大圆不包含这个点. 思路:比较基础的计算几何,要分三种情况,第一种就是这个点在圆外的情况.第二种是点在圆内.第三种是这个点和圆心重合. ac代码 #include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include <string> #includ…

PROBLEM A/_ - Generous Kefa 题 OvO http://codeforces.com/contest/841/problem/A cf 841a 解 只要不存在某个字母,它的个数大于k,即可 #include <iostream> #include <cstring> #include <cstdio> #include <algorithm> #include <cmath> using namespace std;…

转自:http://blog.csdn.net/tyger/article/details/4480029 计算几何题的特点与做题要领:1.大部分不会很难,少部分题目思路很巧妙2.做计算几何题目,模板很重要,模板必须高度可靠.3.要注意代码的组织,因为计算几何的题目很容易上两百行代码,里面大部分是模板.如果代码一片混乱,那么会严重影响做题正确率.4.注意精度控制.5.能用整数的地方尽量用整数,要想到扩大数据的方法(扩大一倍,或扩大sqrt2).因为整数不用考虑浮点误差,而且运算比浮点快. 一.点…

题目1: POJ 2318 TOYS 题目大意: 给一个有n个挡板的盒子,从左到右空格编号为0...n.有好多玩具,问每个玩具在哪个空格里面. 算法讨论: 直接叉积判断就可以.注意在盒子的边界上面也算在盒子里面. #include <cstdio> #include <cstring> #include <cstdlib> #include <iostream> #include <algorithm> #include <cmath>…

//第一期 计算几何题的特点与做题要领: 1.大部分不会很难,少部分题目思路很巧妙 2.做计算几何题目,模板很重要,模板必须高度可靠. 3.要注意代码的组织,因为计算几何的题目很容易上两百行代码,里面大部分是模板.如果代码一片混乱,那么会严重影响做题正确率. 4.注意精度控制. 5.能用整数的地方尽量用整数,要想到扩大数据的方法(扩大一倍,或扩大sqrt2).因为整数不用考虑浮点误差,而且运算比浮点快. 一.点,线,面,形基本关系,点积叉积的理解 POJ 2318 TOYS(推荐) http:/…