从尾到头遍历链表

思路就是递归。

import java.util.ArrayList;

/**
 * Created by itworker365 on 5/12/2017.
 */
public class MainListNodeFromTailToHead {
    public static void main(String[] args) {
        ListNode listNode = new ListNode(1);
        ListNode listNode1 = new ListNode(2);
        ListNode listNode2 = new ListNode(3);
        ListNode listNode3 = new ListNode(4);
        ListNode listNode4 = new ListNode(5);
        listNode.setNext(listNode1);
        listNode1.setNext(listNode2);
        listNode2.setNext(listNode3);
        listNode3.setNext(listNode4);
        MainListNodeFromTailToHead mainListNodeFromTailToHead = new MainListNodeFromTailToHead();
        ArrayList<Integer> res = mainListNodeFromTailToHead.printListFromTailToHead(listNode);
        System.out.println(res.toString());
    }

    //递归添加
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        ArrayList<Integer> res = new ArrayList<>();
        if (listNode == null) {
            return res;
        }
        addListRecur(listNode, res);
        return res;
    }

    public ArrayList<Integer> addListRecur(ListNode listNode, ArrayList<Integer> list){
        if (listNode!= null && listNode.next != null) {
            addListRecur(listNode.next, list);
        }
        list.add(listNode.val);
        return list;
    }
}
class ListNode{
    int val;
    ListNode next = null;
    ListNode(int val) {
        this.val = val;
    }
    public void setNext(ListNode next) {
        this.next = next;
    }
}

 

转载于:https://www.cnblogs.com/it-worker365/p/6845193.html