剑指offer-题5：从尾到头打印链表

清疚 2022-05-30 00:15 131阅读 0赞

## **题目描述** ##

输入一个链表，从尾到头打印链表每个节点的值。

实验平台：[牛客网][Link 1]

--------------------

java:

1.用递归

/**
    *    public class ListNode {
    *        int val;
    *        ListNode next = null;
    *
    *        ListNode(int val) {
    *            this.val = val;
    *        }
    *    }
    *
    */
    import java.util.ArrayList;
    public class Solution {
        ArrayList<Integer> valueList = new ArrayList<Integer>();
        public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
           if(listNode != null){
    			printListFromTailToHead(listNode.next);
    			valueList.add(listNode.val);
    		}
    		return valueList;
        }
    }

2.利用栈

/**
    *    public class ListNode {
    *        int val;
    *        ListNode next = null;
    *
    *        ListNode(int val) {
    *            this.val = val;
    *        }
    *    }
    *
    */
    import java.util.ArrayList;
    import java.util.Stack;
    public class Solution {
        ArrayList<Integer> valueList = new ArrayList<Integer>();
        public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
           Stack<Integer> valueStack = new Stack<Integer>();  // 利用栈
    		ListNode node = listNode;
    		while(node != null){
    			valueStack.push(node.val);
    			node = node.next;
    		}
    		while(valueStack.size() > 0){
    			valueList.add(valueStack.pop());
    		}
    		return valueList;
        }
    }

python:

(用栈，这里我在牛客网上用递归会出问题，大家可以试试)

# -*- coding:utf-8 -*-
    # class ListNode:
    #     def __init__(self, x):
    #         self.val = x
    #         self.next = None
    
    class Solution:
        # 返回从尾部到头部的列表值序列，例如[1,2,3]
        def printListFromTailToHead(self, listNode):
            # write code here
            stack = []
            value_list = []
            node = listNode
            while node is not None:
                stack.append(node)
                node = node.next
            while len(stack) > 0:
                value_list.append(stack[-1].val)
                stack.pop()
            return value_list

[Link 1]: https://www.nowcoder.com/ta/coding-interviews?page=1