数据结构与算法--实现链表的复制(链表中节点比较特殊,含有一个rand指针,指向任意一个节点)

已在leetcode上执行通过

// https://leetcode.com/problems/copy-list-with-random-pointer/  leetcode地址

public class CopyListWithRandom {

    public static class Node {
        int val;
        Node next;
        Node random;

        public Node(int val) {
            this.val = val;
            this.next = null;
            this.random = null;
        }
    }

    public static Node copyRandomList2(Node head) {
        if (head == null) {
            return null;
        }

        Node cur = head;
        Node next;
        while (cur != null){
            next = cur.next;
            Node tmp = new Node(cur.val);
            cur.next = tmp;
            tmp.next = next;
            cur = next;
        }

        cur = head;
        Node curNext;
        while (cur != null){
            curNext = cur.next;
            next = cur.next.next;

            Node rand = cur.random;
            //curNext.random = rand.next;
            curNext.random = rand != null ? rand.next : null;
            cur = next;
        }

        cur = head;
        Node newHead = cur.next;
        while (cur != null){
            curNext = cur.next;
            next = cur.next.next;

            cur.next = next;
            if(next != null) {
                curNext.next = next.next;
            }

            cur = next;
        }

        return newHead;
    }
}