合并两个递增排序的链表

题目：输入两个递增排序的链表，合并这两个链表并使新链表中的结点仍然是按照递增排序的。

package offer;

public class MergeSortedLists {
public static void main(String[] args) {
ListNode node1 = new ListNode(1);
ListNode node2 = new ListNode(3);
ListNode node3 = new ListNode(5);
node1.next = node2;
node2.next = node3;
ListNode node4 = new ListNode(4);
ListNode node5 = new ListNode(6);
ListNode node6 = new ListNode(8);
node4.next = node5;
node5.next = node6;
ListNode node = mergeSortedLists(node1,node4);
node.print(node);
}
//合并两个递增排序的链表
public static ListNode mergeSortedLists(ListNode head1, ListNode head2){
if(head1==null)
return head2;
else if(head2==null)
return head1;
ListNode head = null;
if(head1.val<head2.val){
head = head1;
head.next = mergeSortedLists(head1.next,head2);
}else{
head = head2;
head.next = mergeSortedLists(head1,head2.next);
}
return head;
}
}