//大白p263 #include <cmath> #include <cstdio> #include <cstring> #include <string> #include <queue> #include <functional> #include <set> #include <iostream> #include <vector> #include <algorithm> u…

1.三角形的所有端点 2.过所有三角形的端点对所有圆做切线,得到所有切点. 3.做任意两圆的外公切线,得到所有切点. 对上述所有点求凸包,标记每个点是三角形上的点还是某个圆上的点. 求完凸包后,因为所有点都是按逆时针(或顺时针)排好序的,如果相邻两点在同一圆上,那么求这段圆弧的距离,否则求这段直线的距离.最后得到所有周长. #include <cstdio> #include <cstdlib> #include <cstring> #include <cmath…

Building Fence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)Total Submission(s): 171    Accepted Submission(s): 25Special Judge Problem Description Long long ago, there is a famous farmer named John. He owns a bi…

A - Building Fence Time Limit:1000MS     Memory Limit:65535KB     64bit IO Format:%I64d & %I64u Submit Status Description Long long ago, there is a famous farmer named John. He owns a big farm and many cows. There are two kinds of cows on his farm, o…

题意: 给n个圆和m个三角形,且保证互不相交,用一个篱笆把他们围起来,求最短的周长是多少. 做法:--水过... 把一个圆均匀的切割成500个点,然后求凸包. 注意:求完凸包,在求周长的时候记得要把圆的那部分特殊求. sin(x)  x=PI*(i/j)://度数表示的时候用PI: #include<stdio.h> #include<iostream> #include<math.h> #include<algorithm> #define PI 3.14…

HDU 5130 Signal Interference(计算几何 + 模板) 题目链接http://acm.hdu.edu.cn/showproblem.php?pid=5130 Description Two countries A-Land and B-Land are at war. The territory of A-Land is a simple polygon with no more than 500 vertices. For military use, A-Land co…

题意:给n个圆和m个三角形,且保证互不相交,用一个篱笆把他们围起来,求最短的周长是多少. 解法1:在每个圆上均匀的取2000个点,求凸包周长就可以水过. 解法2:求出所有圆之间的外公切线的切点,以及过三角形每个顶点的的直线和圆的切点,和三角形的三个顶点.这些点做凸包确定篱笆边上的图形.凸包的边和圆弧之和即为所求.求圆弧长度的时候要判断是优弧还是劣弧.用叉积判断两个向量的方向关系即可. //Time:218MS //Memory:860K include <cstdio> #include &l…

大致题意: 给出n个圆和m个三角形,求最小的的,能将所有图形覆盖的图形的周长. 正解为求所有三角形顶点与圆的切点以及圆和圆的切点构造凸包,再求路径. 因为要求结果误差<=1e-3 所以 我们可以在每个圆上,将圆分为1000(或更多)等分,得到每个圆上有1000个点,把这些点和三角形的顶点构造凸包,为减小误差,圆上两点的距离依然为圆弧的长度.这样累加边即可得答案. #include<cstdio> #include<iostream> #include<cstring&g…

整理了一下大白书上的计算几何模板. #include <cstdio> #include <algorithm> #include <cmath> #include <vector> using namespace std; //lrj计算几何模板 struct Point { double x, y; Point(, ) :x(x),y(y) {} }; typedef Point Vector; Point read_point(void) { doub…

HDU 5033 Building(单调栈) 题目链接http://acm.hdu.edu.cn/showproblem.php?pid=5033 Description Once upon a time Matt went to a small town. The town was so small and narrow that he can regard the town as a pivot. There were some skyscrapers in the town, each l…