Heather

lib/possible_bipartition.rb

@@ -1,4 +1,36 @@
 
 def possible_bipartition(dislikes)
-  raise NotImplementedError, "possible_bipartition isn't implemented yet"
+  return true if dislikes.empty? || dislikes.length < 2
+
+  # group_hash includes visited & queued nodes, key is the node & value is the group
+  # group can be 1 or 2
+  group_hash = {}
+  q = []
+
+  # add first, connected node to q & group_hash
+  count = 0
+  i = 0
+  until count == 1 && i < dislikes.length
+    if dislikes[i] != []
+      q << i
+      group_hash[i] = 1
+      count += 1
+    end
+    i += 1
+  end
+
+  while !q.empty?
+    dislikes[q[0]].each do |disliked_dog|
+      parent_group = group_hash[q[0]]
+
+      if group_hash[disliked_dog]
+        return false if group_hash[disliked_dog] == parent_group
+      elsif !group_hash[disliked_dog]
+        q << disliked_dog
+        parent_group == 1 ? group_hash[disliked_dog] = 2 : group_hash[disliked_dog] = 1
+      end
+    end
+    q.shift
+  end
+  return true
 end