Towers of Hanoi: Difference between revisions

Line 2,868:

Also, since the pictorial showing of the moves may be voluminous (especially for a larger number of disks), the move counter is started with the maximum and is the count shown is decremented so the viewer can see how many moves are left to display.

<lang rexx>/*REXX program ~~shows~~ ~~pictorial~~ moves to solve Tower of Hanoi (with N disks).*/

<lang rexx>/*REXX program displays the moves to solve the Tower of Hanoi (with N disks). */

parse arg N .; if ~~N==''~~ ~~then~~ ~~N=3~~ ~~/*Not~~ ~~given?~~ ~~Then~~ ~~use~~ ~~default~~ 3 disks.*/

parse arg N . /*get optional number of disks from CL.*/

if N=='' | N=="," then N=3 /*Not specified? Then use the default.*/

sw=80; wp=sw%3-1; blanks=left('',wp) /*define some default REXX variables. */

~~c.1~~=~~sw%3%2~~ /* ~~[↑]~~ ~~SW:~~ ~~assume default~~ ~~Screen~~ ~~Width~~*/

sw=80; wp=sw%3-1; blanks=left('', wp) /*define some default REXX variables. */

c.1= sw % 3 % 2 /* [↑] SW: assume default Screen Width*/

c.2=sw%2-1

c.3=sw-~~1-c.1-~~1

c.2= sw % 2 - 1

c.3= sw - 1 - c.1 - 1

#=0; z=2**N-1; moveK=z /*#moves; min# of moves; where to move.*/

@abc='abcdefghijklmnopqrstuvwxyN' /*dithering chars when many disks used.*/

~~ebcdic~~= ('f0'~~x==0)~~ /*~~determine~~ if ~~EBCDIC~~ or ~~ASCII~~ ~~machine~~.*/

@abc='abcdefghijklmnopqrstuvwxyN' /*dithering chars when many disks used.*/

ebcdic= ('f0'x==0) /*determine if EBCDIC or ASCII machine.*/

if ebcdic then do; bar='bf'x; ar="df"x; boxen='db9f9caf'x; down="9a"x

if ebcdic then do; bar= 'bf'x; ar= "df"x; boxen= 'db9f9caf'x; down= "9a"x

tr='bc'x; bl="ab"x; br='bb'x; vert="fa"x; tl='ac'x

tr= 'bc'x; bl= "ab"x; br= 'bb'x; vert= "fa"x; tl= 'ac'x

end

else do; bar='c4'x; ar="10"x; boxen='b0b1b2db'x; down="18"x

else do; bar= 'c4'x; ar= "10"x; boxen= 'b0b1b2db'x; down= "18"x

tr='bf'x; bl="c0"x; br='d9'x; vert="b3"x; tl='da'x

tr= 'bf'x; bl= "c0"x; br= 'd9'x; vert= "b3"x; tl= 'da'x

end

verts= vert || vert; Tcorners= tl || tr

downs= down || down; Bcorners= bl || br

box = left(boxen,1); boxChars= boxen || @abc

box = left(boxen, 1); boxChars= boxen || @abc

$.=0; $.1=N; k=N; kk=k+k

do j=1 for N; @.3.j=blanks; @.2.j=blanks; @.1.j=center(copies(box,kk),wp)

do j=1 for N; @.3.j=blanks; @.2.j=blanks; @.1.j=center( copies( box, kk), wp)

if N<=length(boxChars) then @.1.j=translate(@.1.j,,substr(boxChars,kk%2,1),box)

if N<=length(boxChars) then @.1.j= translate(@.1.j, , substr( boxChars, kk%2, 1), box)

kk=kk-2

kk=kk - 2

end /*j*/ /*populate the tower of Hanoi spindles.*/

call ~~showtowers~~; call mov 1,3,N; say

call showTowers; call mov 1,3,N; say

say 'The minimum number of moves to solve a ' N"-disk Tower of Hanoi is " z

exit /*stick a fork in it, we're all done. */

exit

/*──────────────────────────────────────────────────────────────────────────────────────*/

/*─────────────────────────────MOV subroutine─────────────────────────────────*/

⚫

dsk: parse arg from dest; #=#+1; pp=

⚫

if from==1 then do

⚫

pp=overlay(bl, pp, c.1)

⚫

pp=overlay(bar, pp, c.1+1, c.dest-c.1-1, bar) || tr

end

if from==2 then do

lpost=min(2, dest)

hpost=max(2, dest)

if dest==1 then do; pp=overlay(tl, pp, c.1)

⚫

pp=overlay(bar, pp, c.1+1, c.2-c.1-1, bar)||br

⚫

end

⚫

if dest==3 then do; pp=overlay(bl, pp, c.2)

⚫

pp=overlay(bar, pp, c.2+1, c.3-c.2-1, bar)||tr

⚫

end

⚫

end

⚫

if from==3 then do; pp=overlay(br, pp, c.3)

⚫

pp=overlay(bar, pp, c.dest+1, c.3-c.dest-1, bar)

⚫

pp=overlay(tl, pp, c.dest)

⚫

end

⚫

say translate(pp, downs, Bcorners || Tcorners || bar); say overlay(moveK,pp,1)

⚫

say translate(pp, verts, Tcorners || Bcorners || bar)

⚫

say translate(pp, downs, Tcorners || Bcorners || bar); moveK=moveK-1

⚫

$.from=$.from-1; $.dest=$.dest+1; _f=$.from+1; _t=$.dest

⚫

@.dest._t=@.from._f; @.from._f=blanks; call showTowers

⚫

return

/*──────────────────────────────────────────────────────────────────────────────────────*/

mov: if arg(3)==1 then call dsk arg(1) arg(2)

else do; call mov arg(1), 6-arg(1)-arg(2), arg(3)-1

Line 2,904:

Line 2,931:

call mov 6-arg(1)-arg(2), arg(2), arg(3)-1

end

return

/*──────────────────────────────────────────────────────────────────────────────────────*/

/*─────────────────────────────DSK subroutine─────────────────────────────────*/

⚫

showTowers: do j=N by -1 for N; _=@.1.j @.2.j @.3.j; if _\='' then say _; end; return</lang>

⚫

dsk: parse arg from dest; #=#+1; pp=

⚫

if from==1 then do

⚫

pp=overlay(bl, pp, c.1)

⚫

pp=overlay(bar, pp, c.1+1, c.dest-c.1-1, bar) || tr

end

if from==2 then do

lpost=min(2, dest)

hpost=max(2, dest)

if dest==1 then do

⚫

pp=overlay(tl, pp, c.1)

⚫

pp=overlay(bar, pp, c.1+1, c.2-c.1-1, bar)||br

⚫

end

if dest==3 then do

⚫

pp=overlay(bl, pp,c.2)

⚫

pp=overlay(bar, pp,c.2+1, c.3-c.2-1, bar) ||tr

⚫

end

⚫

end

if from==3 then do

⚫

pp=overlay(br, pp, c.3)

⚫

pp=overlay(bar, pp, c.dest+1, c.3-c.dest-1, bar)

⚫

pp=overlay(tl, pp, c.dest)

⚫

end

⚫

say translate(pp, downs, Bcorners || Tcorners || bar); say overlay(moveK,pp,1)

⚫

say translate(pp, verts, Tcorners || Bcorners || bar)

⚫

say translate(pp, downs, Tcorners || Bcorners || bar); moveK=moveK-1

⚫

$.from=$.from-1; $.dest=$.dest+1; _f=$.from+1; _t=$.dest

⚫

@.dest._t=@.from._f; @.from._f=blanks; call ~~showtowers~~

⚫

return

/*─────────────────────────────SHOWTOWERS subroutine──────────────────────────*/

⚫

~~showtowers~~: do j=N by -1 for N; _=@.1.j @.2.j @.3.j; if _\='' then say _; end

return</lang>

'''output'''   when using the default input:

<pre>

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Line 2,983:

The minimum number of moves to solve a 3-disk Tower of Hanoi is 7

</pre>

=={{header|Ring}}==