Largest prime factor: Difference between revisions
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(Largest prime factor in various dialects BASIC (*BASIC256, Chipmunk Basic, **QBasic, *True BASIC, XBasic and Yabasic)) |
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The largest prime factor of 600,851,475,143 is 6857
</pre>
=={{header|Delphi}}==
{{works with|Delphi|6.0}}
{{libheader|Math,SysUtils,StdCtrls}}
<syntaxhighlight lang="Delphi">
function IsPrime(N: int64): boolean;
{Fast, optimised prime test}
var I,Stop: int64;
begin
if (N = 2) or (N=3) then Result:=true
else if (n <= 1) or ((n mod 2) = 0) or ((n mod 3) = 0) then Result:= false
else
begin
I:=5;
Stop:=Trunc(sqrt(N+0.0));
Result:=False;
while I<=Stop do
begin
if ((N mod I) = 0) or ((N mod (I + 2)) = 0) then exit;
Inc(I,6);
end;
Result:=True;
end;
end;
function GetLargestPrimeFact(N: int64): int64;
var J: int64;
begin
J:=3;
while not IsPrime(N) do
begin
if (N mod j) = 0 then N:=N div J;
Inc(J,2);
end;
Result:=N;
end;
procedure TestLargePrimeFact(Memo: TMemo);
var F: integer;
begin
F:=GetLargestPrimeFact(600851475143);
Memo.Lines.Add(IntToStr(F));
end;
</syntaxhighlight>
{{out}}
<pre>
6857
</pre>
=={{header|Elixir}}==
<syntaxhighlight lang="elixir">
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