Paper - Kaylyn

graphs/possible_bipartition.py

@@ -1,12 +1,32 @@
-# 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: ?
+        Time Complexity: O(NE)
+        Space Complexity: O(N)
     """
-    pass
+    # BFS solution
+    N = len(dislikes)
+    colors = [None] * N
+    q = deque()
+    for i in range(N):
+        if colors[i] != None:
+            continue
+        q.append((i, "red"))
+        while q:
+            node, color = q.popleft()
+            temp = "red"
+            if not colors[node]:
+                colors[node] = color
+            for next in dislikes[node]:
+                if colors[next] == colors[node]:
+                    return False
+                elif colors[next] and colors[next] != colors[node]:
+                    continue
+                elif not colors[next] and colors[node] == "red":
+                    temp = "green"
+                q.append((next, temp))
+    return True