给定两个升序排列的单向链表 a、 b ，请设计一个方法合并

public static void mergeList(Node a,Node b){
		Stack<Integer> merged=new Stack<>();
		Node p=a,q=b;
		while(p!=null&&q!=null){
			if(p.value<q.value){
				merged.push(p.value);
				p=p.next;
			}
			if(q.value<p.value){
				merged.push(q.value);
				q=q.next;
			}
		}
		while(p != null){
			merged.push(p.value);
			p=p.next;
		}
		while(q!=null){
			merged.push(q.value);
			q=q.next;
		}
		Node head=new Node();
		head.setValue(merged.pop());
		head.setNext(null);
		Node temp=head;
		while(!merged.isEmpty()){
			Node t=new Node();
			t.setNext(null);
			t.setValue(merged.pop());
			temp.setNext(t);
			temp=t;
		}
		
	}

package algorithm;  public class ConvertLink { private static class Node { int value;  Node next;  } private static void print(Node node) { while (node != null) {
            System.out.println(node.value);  node = node.next;  }
    } /**  * 链表反转  * @param node  * @return  */  private static Node convertLink(Node node) { if (node == null || node.next == null) { return node;  }
        Node preNode = node;  Node editNode = node.next;  Node nextNode = editNode.next;  //循环开始之前必须要先把原来链表的头的next置为空，因为这个节点将是新链表的尾节点  preNode.next = null;  while (editNode != null) {
            editNode.next = preNode;  preNode = editNode;  editNode = nextNode;  if (nextNode != null) {
                nextNode = nextNode.next;  }
        } return preNode;  } /**  * 传入两个链表都是降序排列  *  * @param node1  * @param node2  * @return  */  private static Node mergeTwoLink(Node node1, Node node2) {
        Node nextNode;//先将下一个节点保存起来  Node insertNode;  Node editNode = node1;  Node headNode = node1;  //先判断头节点那个大  if (node1.value > node2.value) {
            insertNode = node2;  }else{
            insertNode = node2.next;  node2.next = node1;  headNode = node2;  editNode = node2;  } while (insertNode != null) {
             nextNode = insertNode.next;  while (editNode != null && editNode.next != null && editNode.next.value > insertNode.value)
                 editNode = editNode.next;  Node editNextNode = editNode.next;  editNode.next = insertNode;  insertNode.next = editNextNode;  insertNode = nextNode;  } return headNode;  } public static void main(String[] args) {
        Node head = new Node();  Node next1 = new Node();  Node next2 = new Node();  Node next3 = new Node();  Node next4 = new Node();   head.value = 5;  head.next = next1;   next1.value = 10;  next1.next = next2;   next2.value = 15;  next2.next = next3;   next3.value = 20;  next3.next = next4;   next4.value = 25;  next4.next = null;    Node head1 = new Node();  Node next21 = new Node();  Node next22 = new Node();   head1.value = 2;  head1.next = next21;   next21.value = 4;  next21.next = next22;   next22.value = 8;  next22.next = null;     System.out.println("convert before ");  System.out.println("node 1");  print(head);  System.out.println("node 2");  print(head1);  head = convertLink(head);  head1 = convertLink(head1);  head = mergeTwoLink(head1,head);  System.out.println("convert after");  print(head);    }

}