ZOJ 2559 The Smart Bomb

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
double distance(double x1,double y1,double x2,double y2)
{
return  sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
}
int main()
{
double x1,x2,x3,y1,y2,y3;
while(scanf("%lf %lf %lf %lf %lf %lf",&x1,&y1,&x2,&y2,&x3,&y3) != EOF)
{
double d1 = distance(x1,y1,x2,y2);
double d2 = distance(x1,y1,x3,y3);
double d3 = distance(x2,y2,x3,y3);
double a,b,c;
a = (d1+d3-d2)*1.0/2;
b = (d2+d3-d1)*1.0/2;
c = (d1+d2-d3)*1.0/2;
printf("%lf\n%lf\n%lf\n",c,a,b);

}
return 0 ;
}