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2016 Update

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Tina Müller 2016-12-05 22:15:40 +01:00
parent 948b86eafa
commit dcf5d15da3
7965 changed files with 139854 additions and 31002 deletions
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59
Task/Power-set/REXX/power-set.rexx
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@ -1,30 +1,29 @@
/*REXX pgm displays a power set, items may be anything (but can't have blanks)*/
parse arg S /*allow the user specify optional set. */
if S='' then S='one two three four' /*None specified? Then use the default*/
N=words(S) /*the number of items in the list (set)*/
@='{}' /*start process with a null power set. */
do chunk=1 for N /*traipse through the items in the set.*/
@=@ combN(N,chunk) /*take N items, a CHUNK at a time. */
end /*chunk*/
w=length(2**N) /*the number of items in the power set.*/
do k=1 for words(@) /* [↓] show combinations, one per line*/
say right(k,w) word(@,k) /*display a single combination to term.*/
end /*k*/
exit /*stick a fork in it, we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
combN: procedure expose S; parse arg x,y; base=x+1; bbase=base-y; !.=0
do p=1 for y; !.p=p; end /*p*/
$=
do j=1; L=
do d=1 for y; L=L','word(S,!.d)
end /*d*/
$=$ '{'strip(L,'L',",")'}'
!.y=!.y+1; if !.y==base then if .combU(y-1) then leave
end /*j*/
return strip($) /*return with a partial powerset chunk.*/
/*────────────────────────────────────────────────────────────────────────────*/
.combU: procedure expose !. y bbase; parse arg d; if d==0 then return 1; p=!.d
do u=d to y; !.u=p+1; if !.u==bbase+u then return .combU(u-1)
p=!.u
end /*u*/
return 0
/*REXX program displays a power set; items may be anything (but can't have blanks).*/
parse arg S /*allow the user specify optional set. */
if S='' then S= 'one two three four' /*Not specified? Then use the default.*/
@='{}' /*start process with a null power set. */
N=words(S); do chunk=1 for N /*traipse through the items in the set.*/
@=@ combN(N, chunk) /*take N items, a CHUNK at a time. */
end /*chunk*/
w=length(2**N) /*the number of items in the power set.*/
do k=1 for words(@) /* [↓] show combinations, one per line*/
say right(k, w) word(@, k) /*display a single combination to term.*/
end /*k*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
combN: procedure expose S; parse arg x,y; base=x+1; bbase=base-y; !.=0
do p=1 for y; !.p=p; end /*p*/
$=
do j=1; L=
do d=1 for y; L=L','word(S, !.d)
end /*d*/
$=$ '{'strip(L, "L", ',')"}"
!.y=!.y+1; if !.y==base then if .combU(y-1) then leave
end /*j*/
return strip($) /*return with a partial powerset chunk.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
.combU: procedure expose !. y bbase; parse arg d; if d==0 then return 1; p=!.d
do u=d to y; !.u=p+1; if !.u==bbase+u then return .combU(u-1)
p=!.u
end /*u*/
return 0