复杂链表的复制

复杂链表的复制

/*
// 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 {
    //用一个哈希表来进行保存
    //key跟value都是node类型
    //key保存当前结点，value保存next以及random指针
    Map<Node, Node> map = new HashMap<Node, Node>();
    public Node copyRandomList(Node head) {
        if (head == null)
            return null;

        if (!map.containsKey(head)) {
            Node temp = new Node(head.val);
            map.put(head, temp);
            temp.next = copyRandomList(head.next);
            temp.random = copyRandomList(head.random);
        }
        return map.get(head);
    }
}