Zebra puzzle: Difference between revisions
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(Added alternative Tailspin solution) |
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=={{header|Tailspin}}== |
=={{header|Tailspin}}== |
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===General solver with relational algebra=== |
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A general solver for this type of puzzle, using relational algebra. This solver can also be used for "Dinesman's multiple-dwelling problem" |
A general solver for this type of puzzle, using relational algebra. This solver can also be used for "Dinesman's multiple-dwelling problem" |
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<lang tailspin> |
<lang tailspin> |
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No more solutions |
No more solutions |
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</pre> |
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===Manual "Norvig" solution=== |
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{{trans|C#}} |
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The streaming syntax of Tailspin lends itself naturally to this solution |
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<lang tailspin> |
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templates permutations |
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when <=1> do [1] ! |
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otherwise |
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def n: $; |
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templates expand |
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def p: $; |
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1..$n -> \(def k: $; |
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[$p(1..$k-1)..., $n, $p($k..last)...] !\) ! |
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end expand |
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$n - 1 -> permutations -> expand ! |
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end permutations |
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def permutationsOf5: [5 -> permutations]; |
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def nationalities: ['Englishman', 'Swede', 'Dane', 'Norwegian', 'German']; |
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def colours: ['red', 'green', 'white', 'yellow', 'blue']; |
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def pets: ['dog', 'birds', 'cats', 'horse', 'zebra']; |
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def drinks: ['tea', 'coffee', 'milk', 'beer', 'water']; |
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def smokes: ['Pall Mall', 'Dunhill', 'Blend', 'Blue Master', 'Prince']; |
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$permutationsOf5... -> $colours($) -> [$... -> {colour: $}] |
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-> \(<[(<{colour: <='green'>}>:<{colour: <='white'>}>)]> $! \) |
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-> \(def current: $; |
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$permutationsOf5... -> $nationalities($) -> \[i]({$current($i), nationality: $}! \) ! |
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\) |
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-> \(<?($(1) <{nationality: <='Norwegian'>}>)> $! \) |
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-> \(<[<{nationality: <='Englishman'>, colour: <='red'>}>]> $! \) |
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-> \(<[(<{nationality: <='Norwegian'>}>:<{colour: <='blue'>}>)] | [(<{colour: <='blue'>}>:<{nationality: <='Norwegian'>}>)]> $! \) |
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-> \(def current: $; |
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$permutationsOf5... -> $drinks($) -> \[i]({$current($i), drink: $}! \) ! |
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\) |
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-> \(<?($(3) <{drink: <='milk'>}>)> $! \) |
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-> \(<[<{drink: <='coffee'>, colour: <='green'>}>]> $! \) |
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-> \(<[<{drink: <='tea'>, nationality: <='Dane'>}>]> $! \) |
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-> \(def current: $; |
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$permutationsOf5... -> $pets($) -> \[i]({$current($i), pet: $}! \)! |
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\) |
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-> \(<[<{nationality: <='Swede'>, pet: <='dog'>}>]> $! \) |
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-> \(def current: $; |
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$permutationsOf5... -> $smokes($) -> \[i]({$current($i), smoke: $}! \)! |
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\) |
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-> \(<[<{smoke: <='Pall Mall'>, pet: <='birds'>}>]> $! \) |
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-> \(<[<{smoke: <='Dunhill'>, colour: <='yellow'>}>]> $! \) |
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-> \(<[(<{smoke: <='Blend'>}>:<{pet: <='cats'>}>)] | [(<{pet: <='cats'>}>:<{smoke: <='Blend'>}>)]> $! \) |
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-> \(<[(<{smoke: <='Dunhill'>}>:<{pet: <='horse'>}>)] | [(<{pet: <='horse'>}>:<{smoke: <='Dunhill'>}>)]> $! \) |
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-> \(<[<{smoke: <='Blue Master'>, drink: <='beer'>}>]> $! \) |
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-> \(<[<{smoke: <='Prince'>, nationality: <='German'>}>]> $! \) |
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-> \(<[(<{smoke: <='Blend'>}>:<{drink: <='water'>}>)] | [(<{drink: <='water'>}>:<{smoke: <='Blend'>}>)]> $! \) |
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-> \[i](when <{pet: <='zebra'>}> do 'The $.nationality; owns the zebra.$#10;' -> !OUT::write $! |
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otherwise $! \) |
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-> \[i]('$i;: $;'! \) -> '$... -> '$;$#10;';$#10;' |
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-> !OUT::write |
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</lang> |
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{{out}} |
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<pre> |
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The German owns the zebra. |
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1: {colour=yellow, drink=water, nationality=Norwegian, pet=cats, smoke=Dunhill} |
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2: {colour=blue, drink=tea, nationality=Dane, pet=horse, smoke=Blend} |
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3: {colour=red, drink=milk, nationality=Englishman, pet=birds, smoke=Pall Mall} |
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4: {colour=green, drink=coffee, nationality=German, pet=zebra, smoke=Prince} |
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5: {colour=white, drink=beer, nationality=Swede, pet=dog, smoke=Blue Master} |
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</pre> |
</pre> |
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