Given a reference of a node in a connected undirected graph.
Return a deep copy (clone) of the graph.
Each node in the graph contains a value (int) and a list (List[Node]) of its neighbors.
class Node {
public int val;
public List<Node> neighbors;
}
Test case format:
For simplicity, each node’s value is the same as the node’s index (1-indexed).
For example, the first node with val == 1, the second node with val == 2, and so on.
The graph is represented in the test case using an adjacency list.
An adjacency list is a collection of unordered lists used to represent a finite graph. Each list describes the set of neighbors of a node in the graph.
The given node will always be the first node with val = 1. You must return the copy of the given node as a reference to the cloned graph.
Test Cases
Input:
(Node) adjList = [[2,4],[1,3],[2,4],[1,3]]
Output:
(Node) [[2,4],[1,3],[2,4],[1,3]]
Input:
(Node) adjList = [[]]
Output:
(Node) [[]]
Input:
(Node) adjList = []
Output:
(Node) []
Solution
/*
// Definition for a Node.
class Node {
public:
int val;
vector<Node*> neighbors;
Node() {
val = 0;
neighbors = vector<Node*>();
}
Node(int _val) {
val = _val;
neighbors = vector<Node*>();
}
Node(int _val, vector<Node*> _neighbors) {
val = _val;
neighbors = _neighbors;
}
};
*/
class Solution {
public:
Node* arr[101];
Node* cloneGraph(Node* node) {
if (node == nullptr) {
return nullptr;
}
if (arr[node->val] != 0) {
return arr[node->val];
}
arr[node->val] = new Node(node->val);
int ns = node->neighbors.size();
for(int i=0; i<ns; i++) {
Node* cloned = cloneGraph(node->neighbors[i]);
arr[node->val]->neighbors.push_back(cloned);
}
return arr[node->val];
}
};class Node {
public int val;
public List<Node> neighbors;
public Node() {
val = 0;
neighbors = new ArrayList<Node>();
}
public Node(int _val) {
val = _val;
neighbors = new ArrayList<Node>();
}
public Node(int _val, ArrayList<Node> _neighbors) {
val = _val;
neighbors = _neighbors;
}
}
class Solution {
public HashMap<Integer, Node> map = new HashMap<>();
public Node cloneGraph(Node node) {
return clone(node);
}
public Node clone(Node node) {
if (node == null) return null;
if (map.containsKey(node.val))
return map.get(node.val);
Node newNode = new Node(node.val, new ArrayList<Node>());
map.put(newNode.val, newNode);
for (Node neighbor : node.neighbors)
newNode.neighbors.add(clone(neighbor));
return newNode;
}
}