面试题06. 从尾到头打印链表

朴灿烈づ我的快乐病毒、 2023-05-28 09:55 50阅读 0赞

# 题目： #

[面试题06. 从尾到头打印链表][06.]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]

# 题解： #

## 1. 题解一： ##

用一个指针遍历链表长度得出数组容量，然后从数组的最后一位开始填充。

## 2. 题解二： ##

反转链表，同时记录链表长度，翻转完成后创建数组，用翻转后的链表给数组赋值，返回数组。

# 代码： #

## 1. 代码一： ##

/** * 面试题06 */
    public class 面试题06 { 
    
        // 解法1：
        public static int[] reversePrint(ListNode head) { 
            ListNode cur = head;
            int len = 0;
            while (cur != null) { 
                len++;
                cur = cur.next;
            }
            int res[] = new int[len];
            ListNode node = head;
            for (int i = len - 1; i >= 0; i--) { 
                res[i] = node.val;
                node = node.next;
            }
            return res;
        }
    
        private static ListNode createLinkedList(int[] arr) { // 将输入的数组输入到链表中
            if (arr.length == 0) { 
                return null;
            }
            ListNode head = new ListNode(arr[0]);
            ListNode current = head;
            for (int i = 1; i < arr.length; i++) { // 过程
                current.next = new ListNode(arr[i]);
                current = current.next;
            }
            return head;
        }
    
        private static void printLinkedList(ListNode head) { // 将链表结果打印
            ListNode current = head;
            while (current != null) { 
                System.out.printf("%d -> ", current.val);
                current = current.next;
            }
            System.out.println("NULL");
        }
    
        public static void main(String[] args) { 
            int x[] = {  1, 3, 2 };
            ListNode list = createLinkedList(x);
            printLinkedList(list);
            int res[] = reversePrint(list);
            for (int i = 0; i < res.length; i++) { 
                System.out.print(res[i] + " ");
            }
            System.out.println();
        }
    }

## 2. 代码二： ##

/** * 面试题06 */
    public class 面试题06 { 
    
        // 解法2：
        public static int[] reversePrint(ListNode head) { 
            ListNode pre = null;
            ListNode cur = head;
            ListNode temp = null;
            int len = 0;
            while (cur != null) { 
                temp = cur.next;
                cur.next = pre;
                pre = cur;
                cur = temp;
                len++;
            }
            int res[] = new int[len];
            ListNode node = pre;
            for (int i = 0; i < len; i++) { 
                res[i] = node.val;
                node = node.next;
            }
            return res;
        }
    
        private static ListNode createLinkedList(int[] arr) { // 将输入的数组输入到链表中
            if (arr.length == 0) { 
                return null;
            }
            ListNode head = new ListNode(arr[0]);
            ListNode current = head;
            for (int i = 1; i < arr.length; i++) { // 过程
                current.next = new ListNode(arr[i]);
                current = current.next;
            }
            return head;
        }
    
        private static void printLinkedList(ListNode head) { // 将链表结果打印
            ListNode current = head;
            while (current != null) { 
                System.out.printf("%d -> ", current.val);
                current = current.next;
            }
            System.out.println("NULL");
        }
    
        public static void main(String[] args) { 
            int x[] = {  1, 3, 2 };
            ListNode list = createLinkedList(x);
            printLinkedList(list);
            int res[] = reversePrint(list);
            for (int i = 0; i < res.length; i++) { 
                System.out.print(res[i] + " ");
            }
            System.out.println();
        }
    }

# 参考： #

1.  [面试题06. 从尾到头打印链表][06. 1]
2.  [面试题06. 从尾到头打印链表（递归法、辅助栈法，清晰图解）][06. 2]

[06.]: https://leetcode-cn.com/problems/cong-wei-dao-tou-da-yin-lian-biao-lcof/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]: /images/20230528/07fa6f43c6ee4310b23b56402d2ed04c.png
[06. 1]: https://leetcode-cn.com/problems/cong-wei-dao-tou-da-yin-lian-biao-lcof/solution/mian-shi-ti-06-cong-wei-dao-tou-da-yin-lian-biao-b/
[06. 2]: https://leetcode-cn.com/problems/cong-wei-dao-tou-da-yin-lian-biao-lcof/solution/mian-shi-ti-06-cong-wei-dao-tou-da-yin-lian-biao-d/