- Clone Graph DaleStudy#259

Author: ayosecu

clone-graph/ayosecu.py

@@ -0,0 +1,85 @@
+from typing import Optional
+from collections import deque
+
+# Definition for a Node.
+class Node:
+    def __init__(self, val = 0, neighbors = None):
+        self.val = val
+        self.neighbors = neighbors if neighbors is not None else []
+
+class Solution:
+    """
+        - Time Complexity: O(N + E)
+            - N = The number of nodes
+            - E = The number of neighbors
+        - Space Complexity: O(N + E)
+    """
+    def cloneGraph(self, node: Optional['Node']) -> Optional['Node']:
+        if not node:
+            return None
+        
+        dq = deque([node])
+        dic = {}
+        dic[node] = Node(node.val)
+
+        while dq:
+            pop_node = dq.popleft()        
+
+            for n in pop_node.neighbors:
+                if n not in dic:
+                    dq.append(n)
+                    dic[n] = Node(n.val)
+                dic[pop_node].neighbors.append(dic[n])
+
+        return dic[node]             
+
+
+### TEST CASES ###
+def build_graph(adj_list):
+    if not adj_list:
+        return None
+
+    nodes = {}
+    for i in range(1, len(adj_list) + 1):
+        nodes[i] = Node(i)
+
+    for i, neighbors in enumerate(adj_list, 1):
+        nodes[i].neighbors = [nodes[n] for n in neighbors]
+
+    return nodes[1]
+
+
+def print_graph(node):
+    if not node:
+        print("None")
+        return
+    
+    visited = set()
+    q = deque([node])
+    while q:
+        curr = q.popleft()
+        if curr in visited:
+            continue
+        visited.add(curr)
+        print(f"Node {curr.val}: {[n.val for n in curr.neighbors]}")
+        for neighbor in curr.neighbors:
+            if neighbor not in visited:
+                q.append(neighbor)
+
+tc = [
+        [[2,4],[1,3],[2,4],[1,3]],
+        [[]],
+        []
+]
+
+sol = Solution()
+for i, adj_list in enumerate(tc, 1):
+    original = build_graph(adj_list)
+    print(f"===== TC {i} =====")
+    print("Original Graph:")
+    print_graph(original)
+
+    cloned = sol.cloneGraph(original)
+
+    print("\nCloned Graph:")
+    print_graph(cloned)