Ying Ye CS fun A

graphs/possible_bipartition.py

@@ -8,5 +8,35 @@ def possible_bipartition(dislikes):
         Time Complexity: ?
         Space Complexity: ?
     """
-    pass
+    # BFS solution
+    if len(dislikes) == 0:
+        return True
+
+
+    def start_new_queue(dislikes, visited):
+        first_item = list(dislikes.keys())[0]
+        visited[first_item] = 0
+        return [first_item]
+
+    visited = {}
+    queue = start_new_queue(dislikes, visited)
+
+    while queue:
+        current = queue.pop(0)
+        curr_color = visited[current]
+        for nbr in dislikes[current]:
+            if nbr not in visited:
+                visited[nbr] = 1 if curr_color == 0 else 0
+                queue.append(nbr)
+            else:
+                if curr_color == visited[nbr]:
+                    return False
+        if len(queue) == 0 and len(visited) < len(dislikes):
+            new_dislikes = {}
+            for key, value in dislikes.items():
+                if key not in visited:
+                    new_dislikes[key] = value
+            dislikes = new_dislikes
+            queue = start_new_queue(dislikes, visited)
+    return True