Surround the Trees Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 10403    Accepted Submission(s): 4033 Problem Description There are a lot of trees in an area. A peasant wants to buy a rope to…

1.HDU 1392 Surround the Trees 2.题意:就是求凸包周长 3.总结:第一次做计算几何,没办法,还是看了大牛的博客 #include<iostream> #include<cstring> #include<cmath> #include<queue> #include<algorithm> #include<cstdio> #include<cstdlib> #define F(i,a,b) f…

Surround the Trees Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10803    Accepted Submission(s): 4187 Problem Description There are a lot of trees in an area. A peasant wants to buy a rope t…

Surround the Trees:http://acm.hdu.edu.cn/showproblem.php?pid=1392 题意: 在给定点中找到凸包,计算这个凸包的周长. 思路: 这道题找出凸包上的点后,s数组中就是按顺序的点,累加一下距离就是周长了. #include <algorithm> #include <iterator> #include <iostream> #include <cstring> #include <cstdli…

题目链接:HDU 1392 Problem Description There are a lot of trees in an area. A peasant wants to buy a rope to surround all these trees. So at first he must know the minimal required length of the rope. However, he does not know how to calculate it. Can you…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1392 这里介绍一种求凸包的算法:Graham.(相对于其它人的解释可能会有一些出入,但大体都属于这个算法的思想,同样可以解决凸包问题) 相对于包裹法的n*m时间,Graham算法在时间上有很大的提升,只要n*log(n)时间就够了.它的基本思想如下: 1.首先,把所有的点按照y最小优先,其次x小的优先排序 2.维护一个栈,用向量的叉积来判断新插入的点跟栈顶的点哪个在外围,如果栈顶的点在当前插入的点的…

Surround the Trees Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6812    Accepted Submission(s): 2594 Problem Description There are a lot of trees in an area. A peasant wants to buy a rope to…

There are a lot of trees in an area. A peasant wants to buy a rope to surround all these trees. So at first he must know the minimal required length of the rope. However, he does not know how to calculate it. Can you help him? The diameter and length…

Shape of HDU Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4972    Accepted Submission(s): 2250 Problem Description 话说上回讲到海东集团推选老总的事情,最终的结果是XHD以微弱优势当选,从此以后,“徐队”的称呼逐渐被“徐总”所取代,海东集团(HDU)也算是名副其实了.…

题目地址:http://acm.hdu.edu.cn/showproblem.php?pid=1392 题意:给出一些点的坐标,求最小的凸多边形把所有点包围时此多边形的周长. 解法:凸包ConvexHull 模板题 #include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<cstdlib> #include<algorithm> #de…