求凸包面积.求结果后不用加绝对值,这是BBS()排序决定的. //Ps 熟练了template <class T>之后用起来真心方便= = //POJ 3348 //凸包面积 //1A 2016-10-15 #include <cstdio> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #define MAXN (10000 +…

Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8122   Accepted: 3674 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are f…

LINK 题意:给出点集,求凸包的面积 思路:主要是求面积的考察,固定一个点顺序枚举两个点叉积求三角形面积和除2即可 /** @Date : 2017-07-19 16:07:11 * @FileName: POJ 3348 凸包面积 叉积.cpp * @Platform: Windows * @Author : Lweleth (SoungEarlf@gmail.com) * @Link : https://github.com/ * @Version : $Id$ */ #include <…

题链: http://poj.org/problem?id=3348 题解: 计算几何,凸包,多边形面积 好吧,就是个裸题,没什么可讲的. 代码: #include<cmath> #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #define MAXN 10050 using namespace std; const double eps=1e-8…

题目传送门 题意:求凸包 + (int)求面积 / 50 /************************************************ * Author :Running_Time * Created Time :2015/11/4 星期三 11:13:29 * File Name :POJ_3348.cpp ************************************************/ #include <cstdio> #include <a…

题目大意:利用n棵树当木桩修建牛圈,知道每头牛需要50平的生存空间,求最多能放养多少头牛. 分析:赤裸裸的求凸包然后计算凸包的面积. 代码如下: ------------------------------------------------------------------------------------------------------------------------------------- #include<iostream> #include<string.h>…

题目链接 大意: 求凸包的面积. #include <iostream> #include <vector> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <map> #include <set> #include <string> #include <queue>…

题目大意: 给你n棵树,可以用这n棵树围一个圈,然后在圈里面可以养牛,每个牛需要50平方米的空间,问最多可以养多少牛? 其实就是求一个凸包,计算凸包面积,然后除以50,然后就得到答案,直接上模板了. 凸包这一类型的题目差不多,可以作为模板使用,时间复杂度是NlogN. //Time 32ms; Memory 568K #include<iostream> #include<algorithm> using namespace std; int n; typedef struct p…

Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 9022   Accepted: 3992 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are f…

裸的凸包,,我就来粘一下板子 把jls和dls的代码混合了一下(雾),感觉我要是能把camp里的几何掌握的差不多就稳         了.(mxy到底打了什么?) 感觉叉积实在是个好东西qwq 今晚cf还要不要打呢,,,可是这几天都是十一点多就早睡了...到时候神智不清怎么办,,,可是好想上个紫什么的... #include <cstdio> #include <cmath> #include <algorithm> #include <vector> us…

Cows Time Limit: 2000MS Memory Limit: 65536K Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are forced to save money on buying fence posts b…

想当年--还是邱神给我讲的凸包来着-- #include <cstdio> #include <cstring> #include <cmath> #include <algorithm> #define eps 0.000000001 #define enter putchar('\n') #define space putchar(' ') using namespace std; typedef long long ll; template <c…

Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6199   Accepted: 2822 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are f…

Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7038   Accepted: 3242 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are f…

Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are forced to save money on buying fence posts by using trees as fence posts wherever possibl…

题目: 给几个点,用绳子圈出最大的面积养牛,输出最大面积/50 题解: Graham凸包算法的模板题 下面给出做法 1.选出x坐标最小(相同情况y最小)的点作为极点(显然他一定在凸包上) 2.其他点进行极角排序<极角指从坐标轴的某一方向逆时针旋转到向量的角度>, 极角一样按距离从近到远(可以用叉积实现) 3.用栈维护凸包上的点,将极点和极角序最小的点依次入栈 4.按顺序扫描,检查栈顶的前两个元素与这个点构成的线段是否拐向右(顺时针侧,叉积小于0) 如果满足就弹出栈顶元素,直到不满足或者栈里不足…

Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8063   Accepted: 3651 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are f…

题目大意: 给定一堆树的点,找到能组合成的最大面积,一个物体占50面积,求最多放多少物体 #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; ; ; double myabs(double x) { ?x:-x; } struct Point{ double x,y; Point( , ):x(x),y(y){}…

Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are forced to save money on buying fence posts by using trees as fence posts wherever possibl…

题目大意: 给定的n个点 能圈出的最大范围中 若每50平方米放一头牛 一共能放多少头 求凸包 答案就是 凸包的面积/50 向下取整 /// 求多边形面积// 凹多边形同样适用 因为点积求出的是有向面积 double areaPg() { ; ;i<k-;i++) // 以t[0]为划分顶点 res+=(t[i]-t[]).det(t[i+]-t[]); return res/2.0; } #include <cstdio> #include <algorithm> #incl…

Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7739   Accepted: 3507 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are f…

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…

//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:/…

凸包真是一个神奇的算法.. 概念 凸包,我理解为凸多边形 叉积 对于向量AB和向量BC,记向量AB*向量BC = AB * BC * sin ∠ABC,而叉积的绝对值其实就是S△ABC/2 对于平面上的一些点,我们要求凸包上所有的点,可以使用Graham算法 时间复杂度O(nlogn) 思路 先找到最左下的点,把其他的点按叉积排序.然后维护一个堆栈,每次利用叉积和栈顶比较判断当前枚举到的点是否是凸包上的点,是则弹出栈顶元素 具体算法Click here 周长 直接所有相邻两点距离相加 面积 多边…

来源 poj 3348 Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with his overseas adventure, they are forced to save money on buying fence posts by using trees as fence posts wherever possibl…

链接:http://poj.org/problem?id=3348 Cows Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6677   Accepted: 3020 Description Your friend to the south is interested in building fences and turning plowshares into swords. In order to help with…

http://poj.org/problem?id=2226 Muddy Fields Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 9022   Accepted: 3348 Description Rain has pummeled the cows' field, a rectangular grid of R rows and C columns (1 <= R <= 50, 1 <= C <= 5…

Halloween treats Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7644   Accepted: 2798   Special Judge Description Every year there is the same problem at Halloween: Each neighbour is only willing to give a certain total number of sweets…

Find a multiple Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7192   Accepted: 3138   Special Judge Description The input contains N natural (i.e. positive integer) numbers ( N <= 10000 ). Each of that numbers is not greater than 15000…

The Pilots Brothers' refrigerator Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 22286   Accepted: 8603   Special Judge Description The game “The Pilots Brothers: following the stripy elephant” has a quest where a player needs to open a…