SRL Archive - Help and Support

I was thinking about perfect numbers last night and made a script for finding them, though it gives me a mathematical "math" error, when it tries to take the square root of 2^32 - 1. Is this some limit in SCAR? Does anyone else know how this script could support larger numbers?

program PerfectNumbers;

function Prime(Num: Integer): Boolean;
var
  i, Sq: Integer;
begin
  Sq := Round(Sqrt(Num));
  for i := 2 to Sq do
    if(Num mod i = 0)then  Exit;
  Result := True;
end;

function PerfectNum(Stop: Integer): Boolean;
var
  Num: Integer;
begin
  for Num := 2 to Stop do
    if(Prime(Round(Pow(2, Num)) - 1))then
      Writeln(FloatToStr(Pow(2, Num - 1) * (Pow(2, Num) - 1)));
end;

begin
  PerfectNum(32);
end.

Hmm…like, did you just copy my Prime Number Function ;)

This is mine:

function PrimeNumber(Number : Integer) : Boolean;
var
  Root : Integer;
  NumberFactors : Integer;
begin
  Root := Round(Sqrt(Number));
  for NumberFactors := 2 to Root do
    if (Number mod NumberFactors) = 0 then
      Exit;
  Result := True;
end;
 

Anyways, my perfect number function:

function PrimeNumber(Number : Integer) : Boolean;
var
  Root : Integer;
  NumberFactors : Integer;
begin
  Root := Round(Sqrt(Number));
  for NumberFactors := 2 to Root do
    if (Number mod NumberFactors) = 0 then
      Exit;
  Result := True;
end;

function GetNumberFactors(Number : Integer) : TIntegerArray;
var
  I : LongInt;
  Root : LongInt;
begin
  SetArrayLength(Result, 1);
  Result[0] := 1;
  Root := Number/2;
  for I := 2 to Root do
  if Number mod I = 0 then
  begin
    SetArrayLength(Result, GetArrayLength(Result) + 1);
    Result[GetArrayLength(Result) - 1] := I;
  end;
end;

function PerfectNumber(Number : Integer) : Boolean;
var
  NumberArray : TIntegerArray;
  NumberSum : Integer;
  I : Integer;
begin
  if PrimeNumber(Number) then
    Exit;
  NumberArray := GetNumberFactors(Number);
  for I := 0 to GetArrayLength(NumberArray) - 1 do
    NumberSum := NumberSum + NumberArray[I];
  if NumberSum = Number then
    Result := True;
end;

begin
  WriteLn(BoolToStr(PerfectNumber(8128)));
end.

Kevin Wolf is going to come along and own me soon :p

As for your error, it's because you need to use a LongInt, not an Integer…since integers can only go up to a certain value.

2 to the power of 32 is larger then the capabilities of an integer,
2 to the power of 31 is 2147483648 which is 1 over it xP

function Prime(Num: Extended): Boolean;
var
  i, Sq: Integer;
begin
  Sq := Round(Sqrt(Num));
  for i := 2 to Sq do
    if(round(Num) mod i = 0)then  Exit;
  Result := True;
end;

Just what I was looking for, thanks :)
How large can an extended be?

Wait… Are you looking for primes or large squares?


And what could you possibly be using these numbers for… Hmmm :p

Extendeds can be WAYYYY bigger.
It only gives you the math error because you have for Blah := 2 TO theInt and the int will be over it's limit and negative now

Ps. LongInt = Integer

Yeah, if you make an integer to large it sets the negative flag :p


Done that a few times in cheat engine…. *cough*CRASHED*cough*

Erm…extendeds have to be decimals…

var
  Rawr: Extended;

begin
  Rawr := 5;
  Writeln(FloatToStr(Rawr));
  Rawr := Sqr(Rawr);
  Writeln(FloatToStr(Rawr));
  Rawr := Sqrt(Rawr);
  Writeln(FloatToStr(Rawr));
end.

I think he means whole numbers. eg, 10^100

ShortInt: -128 / 127 [1 Byte]
Byte: 0 / 255 [1 Byte]
SmallInt: -32,768 / 32,767 [2 Bytes]
Word: 0 / 65,535 [2 Bytes]
LongWord: 0 / 4,294,967,295 [4 Bytes]
LongInt: -2,147,483,648 / 2,147,483,647 [4 Bytes]
Integer: -2,147,483,648 / 2,147,483,647 [4 Bytes]
Int64: -2^63 / 2^63 - 1 [8 Bytes]
Cardinal: 0 / 4,294,967,295 [4 Bytes]

Single: 1.5 x 10^-45 / 3.4 x 10^38 [4 Bytes]
Double: 5 x 10^-324 / 1.7 x 10^308 [8 Bytes]
Extended: 3.4 x 10^-4932 / 1.1 x 10^4932 [10 Bytes]
Currency: -922,337,203,685,477.5808 / 922,337,203,685,477.5807 [8 Bytes]

Part of a tutorial I'm writing… those are the types of number related variables as well as how many bytes they use and their max / min values. I hope this helps a bit…

From: Special Ed
Extended: 3.4 x 10^-4932 / 1.1 x 10^4932 [10 Bytes]

Now that's one hell of a big number (the maximum)! :p