susi939.st

"This solves an Italian magazine's quiz, n. 939;
 you need an implementation for permutationsDo, 
 see miscellanea/gnusmalltalk/permutationsDo.st."

|p1 p2 p3 names perm0 bl1 bl2 bl3|

p1 := #(2 1 4 3 5).
p2 := #(3 4 5 1 2).
p3 := #(1 5 3 2 4).

names := #('Aldo' 'Berto' 'Carlo' 'Dario' 'Enzo').
perm0 := #(1 2 3 4 5).

bl1 := [ :a|
    ((a at: 3) > (a at: 2)) &
    ((a at: 3) < (a at: 5)) ].

bl2 := [ :a|
    ((a at: 1) < (a at: 3)) &
    ((a at: 1) < (a at: 2)) ].

bl3 := [ :a|
    ((a at: 4) < (a at: 3)) &
    (((a at: 1) > (a at: 2)) |
     ((a at: 1) > (a at: 3)) |
     ((a at: 1) > (a at: 4)) |
     ((a at: 1) > (a at: 5)))
    ].

"wraps our constraints check"
OrderedCollection extend [
  controlWith: ruleBlock [
    ^ ruleBlock value: self
  ]
].

"I've implemented permutationsDo for OrderedCollection
 rather than for SequenceableCollection, hence
 we need to convert the Array into an OrderedCollection."
perm0 asOrderedCollection permutationsDo: [:p|
    |pass1 pass2 pass3 assignedNames|

    assignedNames := p collect: [:i| names at: i].

    pass1 := (p collect: [:i| p1 at: i]) controlWith: bl1.
    pass2 := (p collect: [:i| p2 at: i]) controlWith: bl2.
    pass3 := (p collect: [:i| p3 at: i]) controlWith: bl3.

    pass1 & pass2 & pass3
    ifTrue: [
        assignedNames displayNl.
    ].
].