Day08

力扣

/*
// Definition for a Node.
class Node {
    int val;
    Node next;
    Node random;
    public Node(int val) {
        this.val = val;
        this.next = null;
        this.random = null;
    }
}
*/
 
class Solution {
    public Node copyRandomList(Node head) {
        //深拷贝关系相同，地址不同
        if(head == null) {
			return null;
		}
		Node cur = head;
		HashMap map = new HashMap<>();
		while(cur != null) {
			//存放的是旧节点对应的新节点
			map.put(cur,new Node(cur.val));
			cur = cur.next;
		}
		//再次遍历老链表
		cur = head;
		while(cur != null) {
			//取出map中的值,也就是新的节点,进行拷贝连接
			map.get(cur).next = map.get(cur.next);
			map.get(cur).random = map.get(cur.random);
			cur = cur.next;
		}
		//返回老结构对应的头,就是新结构对应的头节点
		return map.get(head);
    }
}