【剑指offer-Java版】26复杂链表的复制

复杂链表复制：

一种思路是通过哈希表存放sibling的配对信息 – 没看明白
一种思路是直接在原始链表中复制，然后拆分 – 属于时间和空间效率都比较高的方式
分三步，还是比较好懂的

    public class _Q26 {

    public ComplexListNode Clone(ComplexListNode list){

        if(list == null) return null;

        CloneNodes(list);
        ConnectSibling(list);
        return ReconnectedNodes(list);
    }

    private void CloneNodes(ComplexListNode list){
        ComplexListNode nextNode = list;

        while(nextNode != null){

            ComplexListNode node = new ComplexListNode<>();

            node.value = nextNode.value;
            node.next = nextNode.next;
            nextNode.next = node;

            nextNode = nextNode.next.next; // 复制之后也是需要 一次走两步的
        }
    }

    private void ConnectSibling(ComplexListNode list){
        ComplexListNode nextNode = list;

        while(nextNode != null){
            if(nextNode.sibling != null){
                nextNode.next.sibling = nextNode.sibling.next;
            }
            nextNode = nextNode.next.next; // 一次跨两步
        }
    }

    private ComplexListNode ReconnectedNodes(ComplexListNode list){

        ComplexListNode result = list.next;

        ComplexListNode node1 = list;
        ComplexListNode node2 = result;

        while(node2 != null){

            if(node2.next == null){
                node1.next = null;
            }else{
                node1.next = node2.next;
                node2.next = node2.next.next;
            }

            node1 = node1.next;
            node2 = node2.next;
        }

        return result;
    }
    }

测试代码：

    public class _Q26Test extends TestCase {

    _Q26 cloneComplexList = new _Q26();

    public void test(){
        ComplexListNode list = new ComplexListNode<>();
        ComplexListNode node1 = new ComplexListNode<>();
        ComplexListNode node2 = new ComplexListNode<>();
        ComplexListNode node3 = new ComplexListNode<>();
        ComplexListNode node4 = new ComplexListNode<>();

        list.value = 'A';
        node1.value = 'B';
        node2.value = 'C';
        node3.value = 'D';
        node4.value = 'E';

        list.next = node1;
        node1.next = node2;
        node2.next = node3;
        node3.next = node4;
        node4.next = null;

        list.sibling = node2;
        node1.sibling = node4;
        node3.sibling = node1;

        System.out.println("===================================before");
        ComplexListNode node = list;
        while(node != null){
            System.out.println(node.value + " - " + (node.sibling == null ? "" : node.sibling.value));
            node = node.next;
        }

        ComplexListNode result = cloneComplexList.Clone(list);

        System.out.println("===================================after");
        ComplexListNode nodeX = result;
        while(nodeX != null){
            System.out.println(nodeX.value + " - " + (nodeX.sibling == null ? "" : nodeX.sibling.value));
            nodeX = nodeX.next;
        }
    }
    }