Nina Patrina -C17 B

graphs/possible_bipartition.py

@@ -1,12 +1,59 @@
 # Can be used for BFS
 from collections import deque 
-
+global color
 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: ?
+        dislikes = { 
+            "Fido": [],
+            "Nala": ["Cooper", "Spot"],
+            "Cooper": ["Nala", "Bruno"],
+            "Spot": ["Nala"],
+            "Bruno": ["Cooper"]
+            }
+        At the first loop we’re going to initiate all nodes with group 01 value. At the second loop for every node that has the group 01 value we’re going to check its neighbors and, if possible, set it a different group value.   
     """
-    pass
+    if not dislikes:
+        return True
+
+    first_dog = list(dislikes.keys())[0]
+
+    q = deque([first_dog])
+    v = []
+    safe_rooms = {}
+    for key in dislikes.keys():
+        safe_rooms[key] = 0
+
+    safe_rooms[first_dog] = 1
+
+    for dog in dislikes:
+        while q:
+            current = q.popleft()
+            v.append(current)
+            if dislikes[current]:
+                for rival in dislikes[current]:
+                    if safe_rooms[rival] == 0:
+                        safe_rooms[rival] = safe_rooms[current] + 1
+                        q.append(rival)
+                    else:
+                        if safe_rooms[rival] == safe_rooms[current]:
+                            return False
+        if dog not in v:
+            q.append(dog)
+
+    return True
+
+
+dislikes = {
+    "Fido": ["Alfie", "Bruno"],
+    "Rufus": ["James", "Scruffy"],
+    "James": ["Rufus", "Alfie"],
+    "Alfie": ["Fido", "James", "T-Bone"],
+    "T-Bone": ["Alfie", "Scruffy"],
+    "Scruffy": ["Rufus", "T-Bone"],
+    "Bruno": ["Fido"]
+}