HDU - 2105The Center of Gravity ————计算几何（求重心）

曾经终败给现在 2022-05-18 09:39 172阅读 0赞

Everyone know the story that how Newton discovered the Universal Gravitation. One day, Newton walked  
leisurely, suddenly, an apple hit his head. Then Newton discovered the Universal Gravitation.From then  
on,people have sovled many problems by the the theory of the Universal Gravitation. What’s more, wo also  
have known every object has its Center of Gravity.  
Now,you have been given the coordinates of three points of a triangle. Can you calculate the center  
of gravity of the triangle?  
**Input**  
The first line is an integer n,which is the number of test cases.  
Then n lines follow. Each line has 6 numbers x1,y1,x2,y2,x3,y3,which are the coordinates of three points.  
The input is terminated by n = 0.  
**Output**  
For each case, print the coordinate, accurate up to 1 decimal places.  
**Sample Input**  
2  
1.0 2.0 3.0 4.0 5.0 2.0  
1.0 1.0 4.0 1.0 1.0 5.0  
0  
**Sample Output**  
3.0 2.7  
2.0 2.3

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三角形重心：  
A(x1,y1)B(x2,y2)C(x3,y3)  A ( x 1 , y 1 ) B ( x 2 , y 2 ) C ( x 3 , y 3 )   
的重心：

(x,y)=(x1\+x2\+x33,y1\+y2\+y33)  ( x , y ) = ( x 1 + x 2 + x 3 3 , y 1 + y 2 + y 3 3 )

--------------------

#include<cstdio>
    #include<cstring>
    #include<iostream>
    #include<algorithm>
    using namespace std;
    typedef long long ll;
    
    
    int main()
    {
        int n;
        double x1,x2,x3,y1,y2,y3;
        while(~scanf("%d",&n)&&n)
        {
            while(n--)
            {
                cin>>x1>>y1>>x2>>y2>>x3>>y3;
                double x=(x1+x2+x3)/3.0;
                double y=(y1+y2+y3)/3.0;
                printf("%.1f %.1f\n",x,y);
            }
        }
        return 0;
    }