40 lines
1.1 KiB
Ruby
40 lines
1.1 KiB
Ruby
def person_is_seller?(name)
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name[-1] == "m"
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end
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class Graph < Hash
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def search(name)
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search_queue = []
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search_queue += self[name]
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# The "searched" Hash is how you keep track of which people you've searched before. We use a hash because hash lookups are fast!
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searched = {}
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until search_queue.empty?
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person = search_queue.shift
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# Only search this person if you haven't already searched them.
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next if searched[person]
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return person if yield person
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search_queue += self[person]
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# Marks this person as searched
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searched[person] = true
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end
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false
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end
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end
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# %w(string1 string2 ...) is a shorter way to define arrays of strings
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graph = Graph.new
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graph["you"] = %w(alice bob claire)
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graph["bob"] = %w(anuj peggy)
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graph["alice"] = %w(peggy)
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graph["claire"] = %w(thom jonny)
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graph["anuj"] = []
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graph["peggy"] = []
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graph["thom"] = []
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graph["jonny"] = []
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# we begin the search from vertex "you" and pass the match criterion in the block, then we tap the search result
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graph.search("you"){|person| person_is_seller?(person)}.tap{|person| puts "#{person} is a mango seller!" if person}
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