RosettaCodeData/Task/ABC-Problem/REXX/abc-problem-2.rexx

104 lines
2.9 KiB
Rexx

/* REXX ---------------------------------------------------------------
* 10.01.2014 Walter Pachl counts the number of possible ways
* 12.01.2014 corrected date and output
*--------------------------------------------------------------------*/
show=(arg(1)<>'')
blocks = 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM'
list = '$ A baRk bOOk trEat coMMon squaD conFuse'
list=translate(list)
Do i=1 To words(blocks)
blkn.i=word(blocks,i)'-'i
blk.i=word(blocks,i)
End
w.=''
wlen=0
Do i=1 To words(list)
w.i=word(list,i)
wlen=max(wlen,length(w.i))
End
Do wi=0 To words(list)
word = w.wi
ways=0
poss.=0
lw=length(word)
cannot=0
Do i=1 To lw /* loop over the characters */
c=substr(word,i,1) /* the current character */
Do j=1 To words(blocks) /* loop over blocks */
blk=word(blocks,j)
If pos(c,blk)>0 Then Do /* block can be used in this position */
z=poss.i.0+1
poss.i.z=j
poss.i.0=z /* number of possible blocks for pos i */
End
End
If poss.i.0=0 Then Do
cannot=1
Leave i
End
End
If cannot=0 Then Do /* no prohibitive character */
s.=0
Do j=1 To poss.1.0 /* build possible strings for char 1 */
z=s.1.0+1
s.1.z=poss.1.j
s.1.0=z
End
Do i=2 To lw /* build possible strings for chars 1 to i */
ii=i-1
Do j=1 To poss.i.0
Do k=1 To s.ii.0
z=s.i.0+1
s.i.z=s.ii.k poss.i.j
s.i.0=z
End
End
End
Do p=1 To s.lw.0 /* loop through all possible strings */
v=valid(s.lw.p) /* test if the string is valid*/
If v Then Do /* it is */
ways=ways+1 /* increment number of ways */
way.ways='' /* and store the string's blocks */
Do ii=1 To lw
z=word(s.lw.p,ii)
way.ways=way.ways blk.z
End
End
End
End
/*---------------------------------------------------------------------
* now show the result
*--------------------------------------------------------------------*/
ol=left(''''word'''',wlen+2)
Select
When ways=0 Then
ol=ol 'cannot be spelt'
When ways=1 Then
ol=ol 'can be spelt'
Otherwise
ol=ol 'can be spelt in' ways 'ways'
End
Say ol'.'
If show Then Do
Do wj=1 To ways
Say copies(' ',10) way.wj
End
End
End
Exit
valid: Procedure
/*---------------------------------------------------------------------
* Check if the same block is used more than once -> 0
* Else: the combination is valid
*--------------------------------------------------------------------*/
Parse Arg list
used.=0
Do i=1 To words(list)
w=word(list,i)
If used.w Then Return 0
used.w=1
End
Return 1