Towers of Hanoi: Difference between revisions
Content added Content deleted
(Frink) |
m (→pictorial moves: added whitespace and comments, elided some unneeded code. .) |
||
Line 4,322:
parse arg N . /*get optional number of disks from CL.*/
if N=='' | N=="," then N=3 /*Not specified? Then use the default.*/
sw= 80;
c.1= sw % 3 % 2 /* [↑] SW: assume default Screen Width*/
c.2= sw % 2 - 1 /* ◄─── C.1 C.2 C.2 are the positions*/
c.3= sw - 2 - c.1 /* of the 3 columns.*/
#= 0; z= 2**N - 1;
@abc= 'abcdefghijklmnopqrstuvwxyN'
ebcdic= ('
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= "
tr= 'bf'x; bl= "c0"x; br= 'd9'x; vert= "b3"x; tl= 'da'x
end
verts= vert || vert;
downs= down || down;
$.= 0; $.1= N; k= N; kk= k + k▼
▲$.=0; $.1=N; k=N; kk=k+k
do j=1 for N; @.3.j= blanks;
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 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. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
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
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,
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
call mov arg(1), arg(2), 1
call mov 6 -arg(1) -arg(2), arg(2), arg(3) -1
end /* [↑] The MOV subroutine is recursive, */
/*──────────────────────────────────────────────────────────────────────────────────────*/
showTowers: do j=N by -1 for N; _=@.1.j @.2.j @.3.j; if _\='' then say _; end; return</lang>
| |||