I cannot pass test10 and i cannot find any mistakes.
Is my algo wrong?
my code:
program p1490;
var
  r,n:int64;
  i:longint;
  x:real;
begin
  readln(r);
  for i:=r-1 downto 0 do
    begin
      x:=sqrt(sqr(r)-sqr(i));
      if x-trunc(x)<1e-10
        then inc(n,r-trunc(x))
        else inc(n,r-trunc(x)-1);
    end;
  writeln(4*(r*r-n));
end.

I have got AC!
I changed "sqr(r)-sqr(i)" into "(r+i)*(r-i)".
Then I don't WA#10 any more, but I don't know why.
Could anyone tell me?
Sorry for my poor English...

Overflow of type.

Edited by author 30.07.2012 20:16

Edited by author 30.07.2012 20:17