LeetCode:随机链表的复制

/*
// 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 {
    public Node copyRandomList(Node head) {
        //null判断
        if(head  == null){
            return null;
        }
        //制造分身
        Node curr = head;
        while(curr != null){
            Node clone = new Node(curr.val);
            clone.next = curr.next;
            curr.next = clone;
            curr = clone.next;
        }
        //复制random指针
        curr = head;
        while(curr != null){
            if(curr.random != null){
                curr.next.random = curr.random.next;
            }
            curr = curr.next.next;
        }
        //分离链表
        curr = head;
        Node cloneHead = head.next;
        Node cloneCurr = cloneHead;
        while(curr != null){
            curr.next = curr.next.next;

            if(cloneCurr.next != null){
                cloneCurr.next = cloneCurr.next.next;
            }

            curr = curr.next;
            cloneCurr = cloneCurr.next;
        }
        return cloneHead;
    }
}

先复制一份相同的节点，指向为A->A'->B->B';

然后将random指针也复制一份；

最后将两组指针进行分离。