链表合并之二

package LinkTogether;

import java.util.ArrayList;
import java.util.LinkedList;

/*
 * 两个升序链表合并，不减顺序输出，使用队列
 * */

class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}

public class Demo05 {
    public static void main(String[] args) {
        ListNode n1 = new ListNode(2);
        ListNode n2 = new ListNode(5);
        ListNode n3 = new ListNode(7);
        ListNode n4 = new ListNode(8);
        n1.next = n2;
        n2.next = n3;
        n3.next = n4;
        
        ListNode n5 = new ListNode(1);
        ListNode n6 = new ListNode(6);
        ListNode n7 = new ListNode(10);
        ListNode n8 = new ListNode(80);
        n5.next = n6;
        n6.next = n7;
        n7.next = n8;
        
        n1 = Merge(n1,n5);
        
        print(n1);
    }
    public static ListNode Merge(ListNode list1,ListNode list2) {
        if(list1 == null && list2 == null)return null;
        if(list1 == null)return list2;
        if(list2 == null)return list1;
        /*
         * 将两个链表分别放在link1和link1中，便于使用相关方法
         * */
        LinkedList<Integer> link1 = new LinkedList<Integer>();
        ListNode temp1 = list1;
        while(temp1 != null){
            link1.add(temp1.val);
            temp1 = temp1.next;
        }
        LinkedList<Integer> link2 = new LinkedList<Integer>();
        ListNode temp2 = list2;
        while(temp2 != null){
            link2.add(temp2.val);
            temp2 =temp2.next;
        }
        /*
         * 将link1和link2中的内容按照不递减的顺序放入arr中
         * */
        ArrayList<Integer> arr = new ArrayList<>();
        while((! link1.isEmpty()) && (! link2.isEmpty())){
            if(link1.element() <= link2.element()){
                arr.add(link1.poll());
            }
            if((link1.isEmpty()) || (link2.isEmpty()))break;
            if(link1.element() > link2.element()){
                arr.add(link2.poll());
            }
        }
        while(! link1.isEmpty()){
            arr.add(link1.poll());
        }
        while(! link2.isEmpty()){
            arr.add(link2.poll());
        }
        /*
         * 将题目中的两个链表相连接，
         * */    
        int flag = 0;
        ListNode temp = list1;
        while(true){
            if(temp.next == null){
                flag ++;
                if(flag == 2)break;
                temp.next = list2;
            }
            temp = temp.next;
        }
        /*
         * 将arr中的数据取出，放入合并后的链表中
         * */
        list1.val = arr.get(0);
        temp = list1.next;
        for(int i=1;i<arr.size();i++){
            temp.val = arr.get(i);
            temp = temp.next;
        }
        return list1;
    }

    private static void print(ListNode n) {
        System.out.println(n.val);
        if(n.next != null){
            print(n.next);
        }
    }
}