Leetcode剑指 Offer 06. 从尾到头打印链表(辅助栈)

Posted 2021-06-07 ！0 ！

题目链接：https://leetcode-cn.com/problems/cong-wei-dao-tou-da-yin-lian-biao-lcof/

解题思路

链表逆序输出就要想到栈结构，直接把链表的所有值存储到栈中，然后栈再弹出到数组

代码

class Solution {
    public int[] reversePrint(ListNode head) {
        Stack<Integer> stack = new Stack<>();
        ListNode t = head;
        while (t != null) {
            stack.push(t.val);
            t = t.next;
        }
        int[] ans = new int[stack.size()];
        for (int i = 0; !stack.isEmpty(); i++) 
            ans[i] = stack.pop();
        return ans;
    }
}

复杂度分析

• 时间复杂度：O(n)
• 空间复杂度：O(n)