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{
This file is part of the Free Pascal run time library.
Copyright (c) 1993-2005 by Florian Klaempfl
Eratos Example, Calculates all Prime Numbers from 1 to max
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
**********************************************************************}
program eratosthenes;
const
{$ifndef MACOS}
max = 1000000;
{$else}
max = 10000; {Actually it works with 100000 also, but not 1000000,}
{in which case the OS refuses to start it.}
{$endif}
var
a : array[1..max] of boolean;
procedure eratos;
var
i,j : longint;
begin
a[1]:=false;
for i:=2 to max do
a[i]:=true;
for i:=2 to max div 2 do
if a[i] then
for j:=2 to max div i do
a[i*j]:=false;
writeln;
j:=0;
for i:=1 to max do
begin
if a[i] then
begin
write(i:7);
inc(j);
if (j mod 10)=0 then
writeln;
end;
end;
writeln;
end;
begin
write('Calculating the Prime Numbers from 1 to ',max,'...');
eratos;
end.
{
$Log: eratos.pp,v $
Revision 1.3 2005/05/14 11:11:33 olle
* Smaller arrray sizes for macos
Revision 1.2 2002/09/07 15:06:35 peter
* old logs removed and tabs fixed
}
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