Ulam spiral (for primes): Difference between revisions
→using FreePascal
Line 3,387:
</lang>
=== using FreePascal ===
{{works with|FreePascal|
<lang Pascal>
PROGRAM Ulam.pas;
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END.
</lang>JPD 2021/06/14
Output:
61 59
37 31
67 17 13
5 3 29
19 2 11 53
41 7
71 23
43 47
73 79
, ,
, ,
, , ,
, , ,
, , , ,
, ,
, ,
, ,
, ,
=== using FreePascal (short version) ===
{{works with|FreePascal| 3.2.0 }}
<lang Pascal>
PROGRAM Ulam8.pas;
{$IFDEF FPC}
{$mode objfpc}{$H+}{$J-}{R+}
{$ELSE}
{$APPTYPE CONSOLE}
{$ENDIF}
(*)
Free `translation` from PHIX for the Spiral part
Free Pascal Compiler version 3.2.0 [2020/06/14] for x86_64
The free and readable alternative at C/C++ speeds
compiles natively to almost any platform, including raspberry PI *
Can run independently from DELPHI / Lazarus
For debian Linux: apt -y install fpc
It contains a text IDE called fp
(*)
USES
crt;
CONST
SIZE = 8 ; // `SIZE = 9 : "The Iceskater" ( Obvious when Dutch ) `
n = SIZE * ord ( Odd ( SIZE ) ) ;
CrLf = #13#10 ;
FUNCTION IsPrime ( n: integer ): boolean ;
VAR
i: integer;
BEGIN
IF ( n < 2 ) THEN Exit ( False ) ;
IF ( n = 2 ) THEN Exit ( True ) ;
IF ( n mod 2 = 0 ) THEN Exit ( False ) ;
FOR i := 3 TO Trunc ( Sqrt ( n ) ) DO
IF ( n mod i = 0 ) THEN Exit( False ) ;
IsPrime := True ;
END;
FUNCTION Spiral ( w, h, x, y : integer ) : integer ;
BEGIN
IF ( y > 0 ) THEN
Spiral := w + Spiral ( h - 1, w, y - 1, w - x - 1 )
ELSE
Spiral := x
END ;
PROCEDURE PrintSpiral ( s : string ) ;
VAR
h : integer = n ;
i : integer ;
j : integer ;
p : integer ;
w : integer = n ;
BEGIN
FOR i := h - 1 DOWNTO 0 DO
BEGIN
FOR j := w - 1 DOWNTO 0 DO
BEGIN
p := w * h - Spiral ( w, h, j, i ) ;
IF IsPrime ( p ) THEN
IF ( s = '' ) THEN Write ( p:3 ) ELSE Write ( '`':3 )
ELSE Write ( ' ':3 )
END;
WriteLn ;
END ;
END ;
BEGIN
IF ( n = 0 ) THEN
BEGIN
WriteLn ( 'Only odd numbers work for SIZE' ) ;
Exit;
END;
PrintSpiral ( '' ) ;
WriteLn ( CrLf ) ;
PrintSpiral ( 'Symbol' ) ;
END.
</lang>JPD 2021/07/04
Output:
61 59
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