Problem: Century Arts has hundreds of art galleries scattered all around the country and you are hired to write a program that determines whether any of the galleries has a critical point. The galleries are polygonal in shape and a critical point is…

鏈接:http://poj.org/problem?id=1279 Art Gallery Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 5337   Accepted: 2277 Description The art galleries of the new and very futuristic building of the Center for Balkan Cooperation have the form…

/* poj 1279 Art Gallery - 求多边形核的面积 */ #include<stdio.h> #include<math.h> #include <algorithm> using namespace std; const double eps=1e-8; struct point { double x,y; }dian[20000+10]; point jiao[203]; struct line { point s,e; double angle;…

计算几何/半平面交 裸的半平面交,关于半平面交的入门请看神犇博客:http://blog.csdn.net/accry/article/details/6070621 然而代码我是抄的proverbs的…… 大体思路是这样的:(一个增量算法) 维护一个当前的半平面交的点集,每次用一条直线去cut它: 依次枚举“凸包”上的点,点在直线左边则保留下来了,否则就丢掉=.= 同时判一下如果“凸包”上连续的两个点分别在直线两侧,就加入这条“凸包”上的线段与直线的交点= = 然后新点集get! 最后求个面积…

地址:http://poj.org/problem?id=1279 题目: Art Gallery Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 7329   Accepted: 2938 Description The art galleries of the new and very futuristic building of the Center for Balkan Cooperation have the f…

Time Limit: 4000ms, Special Time Limit:10000ms, Memory Limit:65536KB Total submit users: 11, Accepted users: 9 Problem 13240 : No special judgement Problem description A long art gallery has 2N rooms. The gallery is laid out as N rows of 2 rooms side…

1279 -- Art Gallery 还是半平面交的问题,要求求出多边形中可以观察到多边形所有边的位置区域的面积.其实就是把每一条边看作有向直线然后套用半平面交.这题在输入的时候应该用多边形的有向面积来判断输入的顺序是顺时针的还是逆时针的. 对于半平面交问题,要注意最后半平面返回的是多少个点.对于小于3个点的情况应该直接返回结果,避免计算过程中产生错误. 代码如下: #include <cstdio> #include <cstring> #include <iostrea…

http://poj.org/problem?id=1279 裸的半平面交的模板,按极角排序后维护一个双端队列,不要忘了最后要去除冗余,即最后一条边(或者更多的边)一定在双端队列里,但它不一定构成半平面,所以要特判. 还有平行的边也要特判,因为平行的边的交点不可求! 最后在poj上用G++交WA了好几次,换用C++就AC了/(ㄒoㄒ)/~~ #include<cmath> #include<cstdio> #include<cstring> #include<al…

题目链接 回忆了一下,半平面交,整理了一下模版. #include <cstdio> #include <cstring> #include <string> #include <cmath> #include <algorithm> using namespace std; #define eps 1e-8 #define N 2001 struct point { double x,y; }p[N],temp[N],pre[N]; int n…

http://poj.org/problem?id=1279 题意:给一个n个点的多边形,n<=1500,求在多边形内能看到所有多边形上的点的面积. #include <cstdio> #include <cstring> #include <cmath> #include <string> #include <iostream> #include <algorithm> #include <queue> #incl…