ural 1348 Goat in the Garden 2

http://acm.timus.ru/problem.aspx?space=1&num=1348

 #include <cstdio>
 #include <cstring>
 #include <cmath>
 #include <algorithm>
 using namespace std;
 const double eps=1e-;

 double dcmp(double x){
     if(fabs(x)<eps) return ;
     else return x<?-:;
 }

 double sqr(double x)
 {
     return x*x;
 }
 struct node
 {
     double x,y;
 }st3,st1,st2;

 double cross(node a,node b)
 {
     return (a.x*b.y-a.y*b.x);
 }
 double dot(node a,node b)
 {
     return (a.x*b.x+a.y*b.y);
 }
 double dis(double x1,double y1,double x2,double y2)
 {
     return sqrt(sqr(x1-x2)+sqr(y1-y2));
 }

 double distance1(node p,node a,node b)
 {
     if(a.x==b.x&&a.y==b.y) return dis(p.x,p.y,a.x,a.y);
     node p1; p1.x=b.x-a.x;p1.y=b.y-a.y;
     node p2; p2.x=p.x-a.x;p2.y=p.y-a.y;
     node p3; p3.x=p.x-b.x;p3.y=p.y-b.y;
     if(dcmp(dot(p1,p2))<) return dis(p.x,p.y,a.x,a.y);
     else if(dcmp(dot(p1,p3))>) return dis(p.x,p.y,b.x,b.y);
     else return (fabs(cross(p1,p2))/dis(a.x,a.y,b.x,b.y));
 }

 int main()
 {
     double x1,y1,x2,y2,x3,y3,l;
     scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
     scanf("%lf%lf%lf",&x3,&y3,&l);
     st1.x=x1;st1.y=y1;
     st2.x=x2;st2.y=y2;
     st3.x=x3;st3.y=y3;
     double l1=dis(st3.x,st3.y,st1.x,st1.y);
     double l2=dis(st3.x,st3.y,st2.x,st2.y);
     double l3=distance1(st3,st1,st2);
     double min1=min(l1,min(l2,l3));
     double max1=max(l1,max(l2,l3));
     double ans1=min1-l;
     double ans2=max1-l;
     if(ans1<eps) ans1=;
     if(ans2<eps) ans2=;
     printf("%.2lf\n",ans1);
     printf("%.2lf\n",ans2);
     return ;
 }