Ulam numbers: Difference between revisions

=={{header|Delphi}}==

{{trans|Phix}}

{{works with|Delphi|6.0}}

{{libheader|SysUtils,StdCtrls}}

<syntaxhighlight lang="Delphi">

function GetUlamNumber(N: integer): integer;

var Ulams: array of integer;

var U,ULen,I: integer;

var Sieve: array of integer;

begin

SetLength(Ulams,Max(N,2));

Ulams[0]:= 1;

Ulams[1]:= 2;

SetLength(Sieve, 2);

Sieve[0]:=1;

Sieve[1]:= 1;

U:=2; ULen:=2;

while Ulen < N do

begin

SetLength(Sieve,U + Ulams[Ulen - 2]);

for I:= 0 to ulen - 2 do

Sieve[u + Ulams[I] - 1]:=Sieve[u + Ulams[i] - 1]+1;

for I:=U to High(Sieve) do

if Sieve[I] = 1 then

begin

U:=I + 1;

Ulams[Ulen]:=U;

Inc(ULen);

break;

end;

end;

Result:=ULams[N - 1];

end;

procedure ShowUlamNumbers(Memo: TMemo);

var N: integer;

var S: string;

begin

N:=1;

while N<=100000 do

begin

S:=Format('Ulam(%d)',[N]);

Memo.Lines.Add(Format('%-12S = %8d', [S, GetUlamNumber(N)]));

N:=N * 10

end;

end;

</syntaxhighlight>

{{out}}

<pre>

Ulam(1) = 1

Ulam(10) = 18

Ulam(100) = 690

Ulam(1000) = 12294

Ulam(10000) = 132788

Ulam(100000) = 1351223

Elapsed Time: 17.685 Sec.

</pre>