Lifting the Stone Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Practice HDU 1115 Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up, a spe…

POJ1385 给定n个顶点 顺序连成多边形 求重心 n<=1e+6 比较裸的重心问题 没有特别数据 由于答案保留两位小数四舍五入 需要+0.0005消除误差 #include<iostream> #include<stdio.h> #include<stdlib.h> #include<string.h> #include<math.h> #include<algorithm> #include<queue> #i…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Problem Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up, a special mecha…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 230 Accepted Submission(s): 130   Problem Description There are many secret openings in the floor which are covered by a big heavy…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5370 Accepted Submission(s): 2239 Problem Description There are many secret openings in the floor which are covered by a big heavy…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4819    Accepted Submission(s): 2006 Problem Description There are many secret openings in the floor which are covered by a big…

转载请注明出处:http://blog.csdn.net/u012860063 题目链接:pid=1115">http://acm.hdu.edu.cn/showproblem.php? pid=1115 Lifting the Stone Problem Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lift…

Lifting the Stone 题目链接: http://acm.hust.edu.cn/vjudge/contest/130510#problem/G Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up, a special mechanism detects this and activates…

Lifting the Stone Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 1115 Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up…

题目: Lifting the Stone Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 168 Accepted Submission(s): 98   Problem Description There are many secret openings in the floor which are covered by a big he…

一.质点系重心公式 x=(x1*m1+x2*m2+x3*m3.....xn*mn)/M  (M=m1+m2+m3+m4...+mn) 二.三角形重心 可直接求得,但在多边形剖分中 各三角形的质点的质量大小不一样 质量大小等于三角形面积. 三.多边形重心 三角形剖分+任意点的三角形剖分+三角形重心+质点系重心公式+任意点的三角形剖分 所以很容易知道一种很优美的计算公式(看代码) #include <cstdio> #include <cstdlib> #include <cma…

Lifting the Stone http://acm.hdu.edu.cn/showproblem.php?pid=1115 题目描述:输入n个顶点(整数),求它们围成的多边形的重心. 算法:以一个点出发,与其他非邻点相连,将n边形划分成n-2个三角形.求每个三角形的质点系重心(如:((x1+x2+x3)/3,(y1+y2+y3)/3)),再求出每个三角形的面积.相乘求和后除以多边形面积). 注意:we connect the points in the given order.输入的顺序,…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6104    Accepted Submission(s): 2546 Problem Description There are many secret openings in the floor which are covered by a big…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5203    Accepted Submission(s): 2155 Problem Description There are many secret openings in the floor which are covered by a big…

Lifting the Stone Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 6971    Accepted Submission(s): 2919 Problem Description There are many secret openings in the floor which are covered by a big…

Problem Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up, a special mechanism detects this and activates poisoned arrows that are shot near the opening. The only possibility i…

题意:求一个不规则简单多边形的重心. 解法:多边形的重心就是所有三角形的重心对面积的加权平均数. 关于求多边形重心的文章: 求多边形重心 用叉积搞一搞就行了. 代码: #include <iostream> #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <algorithm> #define Mod 100000000…

题意   裸的计算几何  求多边形重心: #include<iostream> #include<stdio.h> #include<cstring> #include<algorithm> #include<cmath> using namespace std; double a,b,c,d,e,f; double mix( double x,double y,double xx,double yy ){return x*yy - xx*y;}…

题意:已知一多边形没有边相交,质量分布均匀.顺序给出多边形的顶点坐标,求其重心. 分析: 求多边形重心的题目大致有这么几种: 1,质量集中在顶点上.n个顶点坐标为(xi,yi),质量为mi,则重心 X = ∑( xi×mi ) / ∑mi Y = ∑( yi×mi ) / ∑mi 特殊地,若每个点的质量相同,则 X = ∑xi / n Y = ∑yi / n 2,质量分布均匀.这个题就是这一类型,算法和上面的不同. 特殊地,质量均匀的三角形重心: X = ( x0 + x1 + x2 ) / 3…

多边形重心问题 时间限制:3000 ms  |  内存限制:65535 KB 难度:5   描述 在某个多边形上,取n个点,这n个点顺序给出,按照给出顺序将相邻的点用直线连接, (第一个和最后一个连接),所有线段不和其他线段相交,但是可以重合,可得到一个多边形或一条线段或一个多边形和一个线段的连接后的图形: 如果是一条线段,我们定义面积为0,重心坐标为(0,0).现在求给出的点集组成的图形的面积和重心横纵坐标的和:   输入 第一行有一个整数0<n<11,表示有n组数据:每组数据第一行有一个整…

题意是给一个 n 边形,给出沿逆时针方向分布的各顶点的坐标,求出 n 边形的重心. 求多边形重心的情况大致上有三种: 一.多边形的质量都分布在各顶点上,像是用轻杆连接成的多边形框,各顶点的坐标为Xi,Yi,质量为mi,则重心坐标为: X = ∑( xi * mi ) /  ∑ mi ; Y = ∑( yi * mi)  / ∑ mi; 若每个顶点的质量相等,则重心坐标为: X = ∑ xi / n; Y = ∑ yi / n; 二.多边形的质量分布均匀,像是用密度相同的材料制成的多边形板子,多采…

多边形重心问题 时间限制:3000 ms  |  内存限制:65535 KB 难度:5  描述:在某个多边形上,取n个点,这n个点顺序给出,按照给出顺序将相邻的点用直线连接, (第一个和最后一个连接),所有线段不和其他线段相交,但是可以重合,可得到一           个多边形或一条线段或一个多边形和一个线段的连接后的图形:如果是一条线段,我们定义面积为0,重心坐标为(0,0).现在求给出的点集组成的图形的面积和重心横纵坐标       的和: 输入:第一行有一个整数0<n<11,表示有n组…

思路: 多边形面积->任选一个点,把多边形拆成三角,叉积一下 三角形重心->(x1+x2+x3)/3,(y1+y2+y3)/3 多边形重心公式题目中有,套一下就好了 计算多边形重心方法: (1)划分多边形为三角形:以多边形的一个顶点V为源点(V可取输入的第一个顶点),作连结V与所有非相邻顶点的线段,即将原N边形或分为(N-2)个三角形:(2)求每个三角形的重心和面积:设某个三角形的重心为G(cx,cy),顶点坐标分别为A1(x1,y1),A2(x2,y2),A3(x3,y3),则有cx = (…

多边形重心问题 时间限制:3000 ms  |  内存限制:65535 KB 难度:5   描述 在某个多边形上,取n个点,这n个点顺序给出,按照给出顺序将相邻的点用直线连接, (第一个和最后一个连接),所有线段不和其他线段相交,但是可以重合,可得到一个多边形或一条线段或一个多边形和一个线段的连接后的图形: 如果是一条线段,我们定义面积为0,重心坐标为(0,0).现在求给出的点集组成的图形的面积和重心横纵坐标的和:   输入 第一行有一个整数0<n<11,表示有n组数据: 每组数据第一行有一个…

Problem Description There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up, a special mechanism detects this and activates poisoned arrows that are shot near the opening. The only possibility i…

题目连接:http://acm.hdu.edu.cn/showproblem.php?pid=1115 题意:给你N个点围成的一个多边形,让你求这个多边形的重心. 题解: 将多边形划分为若干个三角形. 若我们求出了每个三角形的重心和质量,可以构造一个新的多边形,顶点为所有三角形的重心,顶点质量为三角形的质量.这个新多边形的质量和重心与原多边形相同,即可使用第一种类型的公式计算出整个多边形的重心. 由于三角形的面积与质量成正比,所以我们这里用面积代替质量来计算. 多边形有可能为凹多边形,三角形有可…

There are many secret openings in the floor which are covered by a big heavy stone. When the stone is lifted up, a special mechanism detects this and activates poisoned arrows that are shot near the opening. The only possibility is to lift the stone…

题目链接:hdu 1115 计算几何求多边形的重心,弄清算法后就是裸题了,这儿有篇博客写得很不错的: 计算几何-多边形的重心 代码如下: #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> using namespace std; ; struct point { double x,y; point() {} point(double x, double y): x(x…

题目链接:http://poj.org/problem?id=1385 题目大意:给你一个多边形的点,求重心. 首先,三角形的重心: ( (x1+x2+x3)/3 , (y1+y2+y3)/3 ) 然后多边形的重心就是将多边形划分成很多个三角形,以三角形面积为权值,将每个三角形的重心加权平均. 注意: pair<double,double>会MLE.. fabs会损失精度?(这个我也不知道),因此在用向量叉积求三角形面积的时候最好是直接让面积求出来就是正的..否则fabs就WA了... 代码:…

我们需要把一块石头平稳的从地板上拿起来.石头的底面是多边形且各个部分的高度都一样,我们需要找出石头的重心. input 测试案例  T; 每组第一行给出N,表示定点数. 接下来N行,每行连个数,表示坐标.定点按顺时针或逆时针给出. output 重心坐标.两个数中间一个空格,每个数保留两位小数. 思路 把多变形分成N-2个三角形,求出重心,重心的质量.(其实是质心) 根据   x=Σ(xi*mi)/Σmi,有因为mi 正比于体积 正比于 面积. 所以利用叉乘求面积. #include"iostr…