Graph Exploration Target: 10s
HashMap maps original → clone. DFS creates clone before recursing neighbors to handle cycles.
def cloneGraph(node):
if not node: return None
cloned = {}
def dfs(n):
if n in cloned: return cloned[n]
copy = Node(n.val)
cloned[n] = copy
for nb in n.neighbors:
copy.neighbors.append(dfs(nb))
return copy
return dfs(node)Type it from memory. Go.