c17 otters - nikki

graphs/possible_bipartition.py

@@ -1,12 +1,35 @@
-# Can be used for BFS
 from collections import deque 
 
 def possible_bipartition(dislikes):
-    """ Will return True or False if the given graph
-        can be bipartitioned without neighboring nodes put
-        into the same partition.
-        Time Complexity: ?
-        Space Complexity: ?
-    """
-    pass
+
+    if not dislikes:
+        return True
+
+    dogs = {dog: -1 for dog in dislikes.keys()}
+
+    def breadth_first(start):
+        dogs[start]
+        q = deque()
+        q.append(start)
+
+        while q:
+            curr = q.popleft()
+            for node in dislikes[curr]:
+
+                if dogs[node] == -1:
+                    dogs[node] = 1 - dogs[curr]
+                    q.append(node)
+
+                elif dogs[node] == dogs[curr]:
+                    return False
+
+        return True
+
+    for dog in dislikes.keys():
+
+        if dogs[dog] == -1:
+            if not breadth_first(dog):
+                return False
+
+    return True