2676: Problem B

#include<stdio.h>
int main()
{
    double x1,x2,x3,y1,y2,y3;
    while(scanf("%lf%lf%lf%lf%lf%lf",&x1,&y1,&x2,&y2,&x3,&y3)==6)
    {
        double x4=(x1+x2)/2,y4=(y1+y2)/2;
        double x5=(x1+x3)/2,y5=(y1+y3)/2;
        double x6=x1+(x2-x1)/3,y6=y1+(y2-y1)/3;
        double x7=x3+(x2-x3)/3,y7=y3+(y2-y3)/3;
        double x=(-x6*(y7-y6)*(x5-x4)+(y6-y4)*(x7-x6)*(x5-x4)+x4*(y5-y4)*(x7-x6))/((x7-x6)*(y5-y4)-(y7-y6)*(x5-x4));
        double y=(y5-y4)*(x-x4)/(x5-x4)+y4;
        printf("%.3lf %.3lf/n",x,y);
    }
    return 0;
}