I've solved this problem but still have WA on test 3.
Could you give me this test or find my mistake plz.
var
l,k,j:integer;
d,d1,d2,m,b:real; t:boolean;
x,y,x1,y1,x2,y2:integer;
label con;
begin
read(x1,y1,x2,y2,x,y,l);
if (((x>=x1)and(x<=x2))or((y>=y1)and(y<=y2)))or
(((x<=x1)and(x>=x2))or((y<=y1)and(y>=y2))) then
 begin
if x2-x1>0 then m:=(y2-y1)/(x2-x1)
else m:=0;
b:=y1-m*x1;
if y=m*x+b then begin d:=0; goto con;end;
if ((m=0)and(y1=y2))or((m=0)and(x1=x2)) then
 begin
 if y1=y2 then d:=abs(y1-y);
 if x1=x2 then d:=abs(x1-x);
 end
else d:=abs(m*x+b-y)/sqrt(m*m);
con:if d-l>0 then writeln((d-l):0:2)
else writeln((1.00-1.00):0:2);
d1:=sqrt(sqr(x-x1)+sqr(y-y1));
d2:=sqrt(sqr(x-x2)+sqr(y-y2));
if (d1>=d2)and(d1-l>=0) then
begin writeln((d1-l):0:2); t:=true;end;
if (d2>d1)and(d2-l>0) then
begin writeln((d2-l):0:2); t:=true;end;
if t=false then write((1.00-1.00):0:2);
t:=false;
halt;
end;
d1:=sqrt(sqr(x-x1)+sqr(y-y1));
d2:=sqrt(sqr(x-x2)+sqr(y-y2));
if (d1>=d2)and(d2-l>=0) then writeln((d2-l):0:2);
if (d1<d2)and(d1-l>0) then writeln((d1-l):0:2);
if (d1>=d2)and(d1-l>=0) then writeln((d1-l):0:2) ;
if (d1<d2)and(d2-l>0) then writeln((d2-l):0:2) ;
end.