D - Blast the Enemy! Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu Submit Status Practice UVALive 4426 Description A new computer game has just arrived and as an active and always-in-the-scene player, you should finish it bef…

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…

思想是分割成三角形,然后求三角形的重心.那么多边形重心就是若干个三角形的重心带权求中心,可以用质点质心公式. #include <cstdio> #include <iostream> #include <algorithm> #include <vector> #include <cstring> #define LL int ; ; LL dp[N]; LL bit[]; using namespace std; struct Point {…

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…

Road Networks Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu Submit Status Practice UVALive 4262 Description   There is a road network comprised by M<tex2html_verbatim_mark> roads and N<tex2html_verbatim_mark> citie…

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(∑( xi×mi ) / ∑mi, ∑( yi×mi ) / ∑mi) 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:(( x0 + x1 + x2 ) / 3,Y = ( y0 + y1 + y2 ) / 3) 以(0,0)为顶点三角剖分之后求三角形重心,把重心连起来转换成质量集中在顶点上的情况求解即可 #include<iostream> #include<cstdio&…

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 = (…

http://acm.hdu.edu.cn/showproblem.php?pid=1115 引用博客:https://blog.csdn.net/ysc504/article/details/8812339 //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…

Long long ago there is a strong tribe living on the earth. They always have wars and eonquer others.One day, there is another tribe become their target. The strong tribe has decide to terminate them!!!There are m villages in the other tribe. Each vil…

Wall Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 28157   Accepted: 9401 Description Once upon a time there was a greedy King who ordered his chief Architect to build a wall around the King's castle. The King was so greedy, that he wo…