Discussion @ 1023. Buttons @ Timus Online Judge

I have AC with such idea but I don't understand how to get a formula or faster solution

Posted by IlushaMax 17 Apr 2016 15:24

var
i,n,l,j:longword; found:boolean;
begin
readln(n);
repeat
found:=False;
for j:=3 to n div 2 do
begin
    if n mod j=0 then
    begin
      found:=True;
      break;
    end;
end;
if found then n:=j;
until not found;
writeln(n-1);
readln;
end.

Please help me to optimize my code. It's 0.405 sec

Re: I have AC with such idea but I don't understand how to get a formula or faster solution

Posted by c_pp 17 Dec 2016 23:35

for j := 3 to sqrt(n) do will help you :)

Re: I have AC with such idea but I don't understand how to get a formula or faster solution

Posted by PO 18 Jan 2019 12:11

> for j := 3 to sqrt(n) do will help you :)

will it? for sqrt(8) = 2.8, but answer should be 4 - 1 = 3

Discussion of Problem 1023. Buttons