Threaded Mode | Linear Mode

Gerald H · 07-20-2017, 05:31 PM

For integer input N the programme returns the Nth digit of the binary Champernowne constant.

For more info see:

https://oeis.org/A030302

Code:

::

  CK1&Dispatch

  BINT1

  ::

    %2

    %LN

    DUP

    %2

    %/

    3PICK

    %1-

    %*

    '

    ID 0

    TRUE

    3PICK3PICK

    '

    DUP

    '

    %EXP

    '

    %*

    '

    %-

    BINT6

    SYMBN

    3PICK

    5PICK

    DUP

    % 500.

    %<=

    ITE

    ::

      %1+

      %LN

      DUP

      % .0195

      %*

      %1+

      %*

      % .665

      %*

      % .04

      %+

    ;

    ::

      DUP

      %4

      %-

      %LN

      SWAP

      %LN

      %1

      OVER

      %1/

      %-

      SWAP

      %LN

      %*

      %-

    ;

    NUMSOLVE

    2DROP

    SWAP

    ?PURGE_HERE

    SWAPDROPSWAP

    %/

    %1+

    %CEIL

    %2

    OVER

    %^

    %2

    OVER

    5PICK

    %+

    %2

    %-

    4PICK

    %MOD

    4PICK

    %-

    %1+

    %^

    4UNROLL

    ROT

    %+

    %1-

    SWAP

    %/

    %1-

    %CEIL

    %*

    %FLOOR

    %2

    %MOD

  ;

;

Gerald H · 07-21-2017, 03:16 PM

If you're doubtful about the values returned by the programme above please compare with the programme below which for integer input N returns the first N digits of the binary Champernowne constant as an integer.

Code:

::

  CK1&Dispatch

  BINT1

  ::

    FPTR2 ^PUSHFLAGS_

    DOBIN

    COERCE

    NULL$

    OVER

    #1+_ONE_DO

    INDEX@

    DO>STR

    BINT3

    OVERLEN$

    #1-SUB$

    &$

    DUPLEN$

    3PICK

    #>=_  That's PTR 3747D

    IT

    ExitAtLOOP

    LOOP

    BINT1

    ROT

    SUB$

    FPTR2 ^POPFLAGS_

    FPTR2 ^S>Z

  ;

;