Zebra puzzle
var CONTENT = Hash(
:House => nil,
:Nationality => [:English, :Swedish, :Danish, :Norwegian, :German],
:Colour => [:Red, :Green, :White, :Blue, :Yellow],
:Pet => [:Dog, :Birds, :Cats, :Horse, :Zebra],
:Drink => [:Tea, :Coffee, :Milk, :Beer, :Water],
:Smoke => [:PallMall, :Dunhill, :BlueMaster, :Prince, :Blend]
)
func adjacent(n,i,g,e) {
(0..3).any {|x| (n[x]==i && g[x+1]==e) || (n[x+1]==i && g[x]==e) }
}
func leftof(n,i,g,e) {
(0..3).any {|x| n[x]==i && g[x+1]==e }
}
func coincident(n,i,g,e) {
n.indices.any {|x| n[x]==i && g[x]==e }
}
func solve {
CONTENT{:Nationality}.permutations{|*nation|
nation.first == :Norwegian ->
&& CONTENT{:Colour}.permutations {|*colour|
leftof(colour,:Green,colour,:White) ->
&& coincident(nation,:English,colour,:Red) ->
&& adjacent(nation,:Norwegian,colour,:Blue) ->
&& CONTENT{:Pet}.permutations {|*pet|
coincident(nation,:Swedish,pet,:Dog) ->
&& CONTENT{:Drink}.permutations {|*drink|
drink[2] == :Milk ->
&& coincident(nation,:Danish,drink,:Tea) ->
&& coincident(colour,:Green,drink,:Coffee) ->
&& CONTENT{:Smoke}.permutations {|*smoke|
coincident(smoke,:PallMall,pet,:Birds) ->
&& coincident(smoke,:Dunhill,colour,:Yellow) ->
&& coincident(smoke,:BlueMaster,drink,:Beer) ->
&& coincident(smoke,:Prince,nation,:German) ->
&& adjacent(smoke,:Blend,pet,:Cats) ->
&& adjacent(smoke,:Blend,drink,:Water) ->
&& adjacent(smoke,:Dunhill,pet,:Horse) ->
&& return [nation,colour,pet,drink,smoke]
} } } } } }
var res = solve();
var keys = [:House, :Nationality, :Colour, :Pet, :Drink, :Smoke]
var width = keys.map{ .len }
var fmt = width.map{|w| "%-#{w+2}s" }.join(" ")
say "The Zebra is owned by the man who is #{res[0][res[2].first_index(:Zebra)]}\n"
say (fmt % keys..., "\n", fmt % width.map{|w| "-"*w }...)
res[0].indices.map{|i| res.map{|a| a[i] }}.each_kv {|k,v| say fmt%(k,v...) }
Output:
The Zebra is owned by the man who is German
House Nationality Colour Pet Drink Smoke
----- ----------- ------ --- ----- -----
0 Norwegian Yellow Cats Water Dunhill
1 Danish Blue Horse Tea Blend
2 English Red Birds Milk PallMall
3 German Green Zebra Coffee Prince
4 Swedish White Dog Beer BlueMaster
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