求重力，这个问题具体怎么用C语言来解决呢

Problem Description
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

https://www.cnblogs.com/cmmdc/p/6803072.html

回答你的问题还必须得英语好，还好有翻译软件，好多年没有用过C了，这次写一大堆问题，不过还是解决了，可能写的不是那么好

#include "stdio.h"
float *centerFun(float axis[]);
void main(){
    int num=0;
    int i=0;
    float f=0;
    float axis[6];

    printf("Please enter the total number of rows\n");
    scanf("%d",&num);

    for (i=0;i<num;i++)
    {
        int j=0;
        float *center;
        printf("Please enter the three coordinate points of the %d line\n",i+1);
        for(j=0;j<6;j++){
            scanf("%f",&f);
            axis[j]=f;
        }
        center  =centerFun(axis);
        printf("(%.1f,%.1f)\n",center[0],center[1]);
    }

    system("pause");

}
float *centerFun(float * axis){
    float center[2];
    center[0]=(float)((axis[0]+axis[2]+axis[4])/3);
    center[1]=(float)((axis[1]+axis[3]+axis[5])/3);
    return center;

}