Amy W

lib/possible_bipartition.rb

@@ -1,4 +1,47 @@
+require "set"
 
 def possible_bipartition(dislikes)
-  raise NotImplementedError, "possible_bipartition isn't implemented yet"
+  if dislikes.empty?
+    return true
+  end
+
+  dogz = Set.new()
+  doggos = Set.new()
+
+  i = 0
+  return bipartition_helper(i, dislikes, dogz, doggos)
+end
+
+def bipartition_helper(i, dislikes, dogz, doggos)
+  while i < dislikes.length
+    dislike = dislikes[i]
+    if !dogz.include?(i) && !doggos.include?(i)
+      dogz1 = dogz.clone()
+      doggos1 = doggos.clone()
+
+      dogz1.add(i)
+      doggos.add(i)
+
+      return bipartition_helper(i, dislikes, dogz1, doggos1) || bipartition_helper(i, dislikes, dogz, doggos)
+    elsif dogz.include?(i)
+      dislike.each { |dog|
+        if dogz.include?(dog)
+          return false
+        else
+          doggos.add(dog)
+        end
+      }
+    elsif doggos.include?(i)
+      dislike.each { |dog|
+        if doggos.include?(dog)
+          return false
+        else
+          dogz.add(dog)
+        end
+      }
+    end
+
+    i += 1
+  end
+  return true
 end