text: #include <stdio.h>
  #include <math.h>
  
  struct point{
  	double x;
  	double y;
  };
  
  int main(){
  	double distance(struct point p1,struct point p2);
  	struct point a={1,2},b={4,6};
  	printf("a=(%.lf,%.lf) b=(%.lf,%.lf)\n",a.x,a.y,b.x,b.y);
  	printf("distance=%.lf\n",distance(a,b));
  	return 0;
  }
  
  double distance(struct point p1,struct point p2)
  {
  	return sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
  }
  