Earth - Beauttie

lib/possible_bipartition.rb

@@ -1,4 +1,26 @@
 
 def possible_bipartition(dislikes)
-  raise NotImplementedError, "possible_bipartition isn't implemented yet"
+  return true if dislikes.empty? 
+
+  group_num = Array.new(dislikes.length)
+  # Element at index i indicates group number for dog i
+  group_num[0] = 1
+  queue = Queue.new
+  queue.enq(0)
+  while !queue.empty?
+    current = queue.deq
+    dislikes[current].each do |dog|
+      if group_num[dog].nil?
+        # Assign dogs disliked by the current dog to the other group
+        group_num[dog] = group_num[current] == 1 ? 2 : 1
+        queue.enq(dog)
+      # If a dog disliked by the current dog is in the same group
+      elsif group_num[dog] == group_num[current]
+        return false
+      end
+    end
+    queue.enq(current + 1) if dislikes[current].empty?
+  end
+
+  return true
 end