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…

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…

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…

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…

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…

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: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…

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…

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…