code for chapter 6 in ruby

06_breadth-first_search/ruby/01_breadth-first_search.rb

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+def person_is_seller(name)
+  name[-1] == "m"
+end
+
+@graph = {}
+
+# %w(string1 string2 ...) is a shorter way to define arrays of strings
+@graph["you"] = %w(alice bob claire)
+@graph["bob"] = %w(anuj peggy)
+@graph["alice"] = %w(peggy)
+@graph["claire"] = %w(thom jonny)
+@graph["anuj"] = []
+@graph["peggy"] = []
+@graph["thom"] = []
+@graph["jonny"] = []
+
+def search(name)
+  search_queue = []
+  search_queue += @graph[name]
+  # This array is how you keep track of which people you've searched before.
+  searched = []
+
+  until search_queue.empty?
+    person = search_queue.shift
+    # Only search this person if you haven't already searched them.
+    next if searched.member?(person)
+    if person_is_seller(person)
+      puts "#{person} is a mango seller!"
+      return true
+    else
+      search_queue += @graph[person]
+      # Marks this person as searched
+      searched.push(person)
+    end
+  end
+
+  false
+end
+
+search("you")