Rosetta Code

Towers of Hanoi: Difference between revisions

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Towers of Hanoi (view source)

Revision as of 02:12, 20 August 2016

585 bytes added ,  7 years ago
m
→‎pictorial moves: added/changed comments and whitespace, changed indentations.
m (→‎simple text moves: added/changed comments and whitespace.)
m (→‎pictorial moves: added/changed comments and whitespace, changed indentations.)
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 pictorialdisplays 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 /*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.1sw=sw%3%2 80; wp=sw%3-1; blanks=left('', wp) /*define [↑]some default SW:REXX assume defaultvariables. Screen Width*/
c.1= sw % 3 % 2 /* [↑] SW: assume default Screen Width*/
c.2=sw%2-1
c.32= sw % 2 -1-c.1- 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@abc= ('f0abcdefghijklmnopqrstuvwxyN'x==0) /*determinedithering ifchars EBCDICwhen ormany ASCIIdisks machineused.*/
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
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
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
$.=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)
if N<=length(boxChars) then @.1.j= translate(@.1.j, , substr( boxChars, kk%2, 1), box)
kk=kk - 2
end /*j*/ /*populate the tower of Hanoi spindles.*/
 
call showtowersshowTowers; 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 showtowersshowTowers▼
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 ⟶ 2,931:
call mov 6-arg(1)-arg(2), arg(2), arg(3)-1
end
return
/*──────────────────────────────────────────────────────────────────────────────────────*/
/*─────────────────────────────DSK subroutine─────────────────────────────────*/
showtowersshowTowers: 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''' &nbsp; when using the default input:
<pre>
Line 2,986 ⟶ 2,983:
The minimum number of moves to solve a 3-disk Tower of Hanoi is 7
</pre>
 
 
=={{header|Ring}}==
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