Re: [閒聊] 每日leetcode

[sustainer123 (caster )]

※ 引述《Rushia (早瀬ユウカの体操服 )》之銘言：
: https://leetcode.com/problems/remove-nodes-from-linked-list/description/
: 2487. Remove Nodes From Linked List
: 給你一個鏈結串列，移除串列中所有右邊存在比他大的數字的的節點。
: https://assets.leetcode.com/uploads/2022/10/02/drawio.png
: 思路:
: 1.題目其實是在求一個最長遞減串列，我們將原串列做反轉之後把遞增的串起來，再把
:   串起來的串列也反轉即可。
: py code:
: ----------------------------------------------
: class Solution:
:     def removeNodes(self, head: Optional[ListNode]) -> Optional[ListNode]:
:         def reverse(node: Optional[ListNode]):
:             curr, prev = node, None
:             while curr:
:                 tmp = curr.next
:                 curr.next = prev
:                 prev = curr
:                 curr = tmp
:             return prev
:         head = reverse(head)
:         dummy = ListNode(-1)
:         curr = dummy
:         while head:
:             if head.val >= curr.val:
:                 curr.next = head
:                 curr = curr.next
:             head = head.next
:         curr.next = None
:         return reverse(dummy.next)
: ----------------------------------------------

照抄大老思路

Java Code:
/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public  ListNode reverse(ListNode node){
        ListNode pre = null;
        ListNode cur = node;

        while(cur != null){
            ListNode tmp = cur.next;
            cur.next = pre;
            pre = cur;
            cur = tmp;
        }
        return pre;
    }

    public ListNode removeNodes(ListNode head) {
        head = reverse(head);
        ListNode dummy = new ListNode();
        ListNode cur = dummy;

        while(head != null){
            if(head.val >= cur.val){
                cur.next = head;
                cur = head;
            }
            head = head.next;
        }
        cur.next = null;
        return reverse(dummy.next);


    }
}


1 Java函式裡面不能放函式
2 分號
3 static可以理解成全域變數ㄇ

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推 JIWP: 別卷了
推 digua: 大師
推 wu10200512: static跟全域變數滿像的
→ wu10200512: 只是你放在class裡就只能用class的static函數改
推 JIWP: 跟C的static一樣嗎
推 wu10200512: java就是換皮c++
→ sustainer123: 我C++沒學好QQ
推 SecondRun: 不如C#
→ JIWP: 剩我不會c++了
→ JIWP: 要不要試試看用monotonic stack來解這一題
→ sustainer123: 我想一下怎解
→ DJYOSHITAKA: 剩我只會一種語言了
→ sustainer123: 老實講我也只熟python C學過一年但寫得不怎麼樣
→ sustainer123: 其他就摸過而已