27 lines
697 B
Crystal
27 lines
697 B
Crystal
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require "./spec_helper"
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describe Graph do
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describe "#find_path" do
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it "reports no paths in a graph with no edges" do
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gr = Graph(String).new
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elems = ["a", "b", "c", "d"]
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elems.each &->gr.add_node(String)
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elems.each do |elem|
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elems.each do |other|
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next if elem == other
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gr.find_path(elem, other).should be_nil
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end
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end
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end
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it "computes the shortest path" do
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gr = Graph(String).new
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[{"a", "b", 1}, {"a", "c", 1}, {"c", "b", 1}, {"b", "d", 1}].each do |t|
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from, to, cost = t
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gr.add_edge(from, to, cost)
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end
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gr.find_path("a", "d").should eq({["a", "b", "d"], 2})
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end
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end
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end
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