[ 오늘의 코테 연습장 ] [ LeetCode ] Clone Graph

📑 문제
https://leetcode.com/problems/clone-graph/

📑 문제 접근 방법

이문제는 graph문제이기 때문에, DFS 알고리즘을 이용하여 해결했습니다. 

1. 복제한 노드를 저장하기 위해 HashMap을 생성
2. 현재 노드를 복제 , 이웃 노드를 재귀적으로 탐색하며 복제하기 위해 DFS 알고리즘 사용 


📑 CODE 

/*
// Definition for a Node.
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 {
          HashMap<Integer, Node> visited = new HashMap<>();

    public Node cloneGraph(Node node) {
      
        if (node == null) return null;
        if (visited.containsKey(node.val)) return visited.get(node.val);
        
        Node copyNode = new Node();
        copyNode.val = node.val; 
        visited.put(node.val, copyNode);
        
        for (Node neighbor : node.neighbors) {
            copyNode.neighbors.add(cloneGraph(neighbor));
        }
        
        return copyNode;
    }
}