23 lines
625 B
Elixir
23 lines
625 B
Elixir
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defmodule Dominoes do
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@type domino :: {1..6, 1..6}
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@doc """
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chain?/1 takes a list of domino stones and returns boolean indicating if it's
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possible to make a full chain
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"""
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@spec chain?(dominoes :: [domino]) :: boolean
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def chain?([]), do: true
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def chain?([{first, second}]) when first == second, do: true
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def chain?([{first, second} | dominoes]) do
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Enum.any?(
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dominoes,
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fn
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{^first, x} = domino -> chain?([{second, x} | List.delete(dominoes, domino)])
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{x, ^first} = domino -> chain?([{second, x} | List.delete(dominoes, domino)])
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_ -> false
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end
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)
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end
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end
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