mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
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168 lines
21 KiB
JSON
168 lines
21 KiB
JSON
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"question": {
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"questionId": "2216",
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"questionFrontendId": "2095",
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"boundTopicId": null,
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"title": "Delete the Middle Node of a Linked List",
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"titleSlug": "delete-the-middle-node-of-a-linked-list",
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"content": "<p>You are given the <code>head</code> of a linked list. <strong>Delete</strong> the <strong>middle node</strong>, and return <em>the</em> <code>head</code> <em>of the modified linked list</em>.</p>\n\n<p>The <strong>middle node</strong> of a linked list of size <code>n</code> is the <code>⌊n / 2⌋<sup>th</sup></code> node from the <b>start</b> using <strong>0-based indexing</strong>, where <code>⌊x⌋</code> denotes the largest integer less than or equal to <code>x</code>.</p>\n\n<ul>\n\t<li>For <code>n</code> = <code>1</code>, <code>2</code>, <code>3</code>, <code>4</code>, and <code>5</code>, the middle nodes are <code>0</code>, <code>1</code>, <code>1</code>, <code>2</code>, and <code>2</code>, respectively.</li>\n</ul>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2021/11/16/eg1drawio.png\" style=\"width: 500px; height: 77px;\" />\n<pre>\n<strong>Input:</strong> head = [1,3,4,7,1,2,6]\n<strong>Output:</strong> [1,3,4,1,2,6]\n<strong>Explanation:</strong>\nThe above figure represents the given linked list. The indices of the nodes are written below.\nSince n = 7, node 3 with value 7 is the middle node, which is marked in red.\nWe return the new list after removing this node. \n</pre>\n\n<p><strong>Example 2:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2021/11/16/eg2drawio.png\" style=\"width: 250px; height: 43px;\" />\n<pre>\n<strong>Input:</strong> head = [1,2,3,4]\n<strong>Output:</strong> [1,2,4]\n<strong>Explanation:</strong>\nThe above figure represents the given linked list.\nFor n = 4, node 2 with value 3 is the middle node, which is marked in red.\n</pre>\n\n<p><strong>Example 3:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2021/11/16/eg3drawio.png\" style=\"width: 150px; height: 58px;\" />\n<pre>\n<strong>Input:</strong> head = [2,1]\n<strong>Output:</strong> [2]\n<strong>Explanation:</strong>\nThe above figure represents the given linked list.\nFor n = 2, node 1 with value 1 is the middle node, which is marked in red.\nNode 0 with value 2 is the only node remaining after removing node 1.</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li>The number of nodes in the list is in the range <code>[1, 10<sup>5</sup>]</code>.</li>\n\t<li><code>1 <= Node.val <= 10<sup>5</sup></code></li>\n</ul>\n",
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"difficulty": "Medium",
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"exampleTestcases": "[1,3,4,7,1,2,6]\n[1,2,3,4]\n[2,1]",
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"code": "/**\n * Definition for singly-linked list.\n * struct ListNode {\n * int val;\n * ListNode *next;\n * ListNode() : val(0), next(nullptr) {}\n * ListNode(int x) : val(x), next(nullptr) {}\n * ListNode(int x, ListNode *next) : val(x), next(next) {}\n * };\n */\nclass Solution {\npublic:\n ListNode* deleteMiddle(ListNode* head) {\n \n }\n};",
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"code": "/**\n * Definition for singly-linked list.\n * public class ListNode {\n * int val;\n * ListNode next;\n * ListNode() {}\n * ListNode(int val) { this.val = val; }\n * ListNode(int val, ListNode next) { this.val = val; this.next = next; }\n * }\n */\nclass Solution {\n public ListNode deleteMiddle(ListNode head) {\n \n }\n}",
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"code": "# Definition for singly-linked list.\n# class ListNode(object):\n# def __init__(self, val=0, next=None):\n# self.val = val\n# self.next = next\nclass Solution(object):\n def deleteMiddle(self, head):\n \"\"\"\n :type head: Optional[ListNode]\n :rtype: Optional[ListNode]\n \"\"\"\n ",
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"code": "# Definition for singly-linked list.\n# class ListNode:\n# def __init__(self, val=0, next=None):\n# self.val = val\n# self.next = next\nclass Solution:\n def deleteMiddle(self, head: Optional[ListNode]) -> Optional[ListNode]:\n ",
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"code": "/**\n * Definition for singly-linked list.\n * struct ListNode {\n * int val;\n * struct ListNode *next;\n * };\n */\n\n\nstruct ListNode* deleteMiddle(struct ListNode* head){\n\n}",
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"code": "/**\n * Definition for singly-linked list.\n * public class ListNode {\n * public int val;\n * public ListNode next;\n * public ListNode(int val=0, ListNode next=null) {\n * this.val = val;\n * this.next = next;\n * }\n * }\n */\npublic class Solution {\n public ListNode DeleteMiddle(ListNode head) {\n \n }\n}",
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"code": "/**\n * Definition for singly-linked list.\n * function ListNode(val, next) {\n * this.val = (val===undefined ? 0 : val)\n * this.next = (next===undefined ? null : next)\n * }\n */\n/**\n * @param {ListNode} head\n * @return {ListNode}\n */\nvar deleteMiddle = function(head) {\n \n};",
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"code": "# Definition for singly-linked list.\n# class ListNode\n# attr_accessor :val, :next\n# def initialize(val = 0, _next = nil)\n# @val = val\n# @next = _next\n# end\n# end\n# @param {ListNode} head\n# @return {ListNode}\ndef delete_middle(head)\n \nend",
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"lang": "Swift",
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"code": "/**\n * Definition for singly-linked list.\n * public class ListNode {\n * public var val: Int\n * public var next: ListNode?\n * public init() { self.val = 0; self.next = nil; }\n * public init(_ val: Int) { self.val = val; self.next = nil; }\n * public init(_ val: Int, _ next: ListNode?) { self.val = val; self.next = next; }\n * }\n */\nclass Solution {\n func deleteMiddle(_ head: ListNode?) -> ListNode? {\n \n }\n}",
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"lang": "Go",
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"code": "/**\n * Definition for singly-linked list.\n * type ListNode struct {\n * Val int\n * Next *ListNode\n * }\n */\nfunc deleteMiddle(head *ListNode) *ListNode {\n \n}",
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"code": "/**\n * Definition for singly-linked list.\n * class ListNode(_x: Int = 0, _next: ListNode = null) {\n * var next: ListNode = _next\n * var x: Int = _x\n * }\n */\nobject Solution {\n def deleteMiddle(head: ListNode): ListNode = {\n \n }\n}",
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"code": "/**\n * Example:\n * var li = ListNode(5)\n * var v = li.`val`\n * Definition for singly-linked list.\n * class ListNode(var `val`: Int) {\n * var next: ListNode? = null\n * }\n */\nclass Solution {\n fun deleteMiddle(head: ListNode?): ListNode? {\n \n }\n}",
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"code": "// Definition for singly-linked list.\n// #[derive(PartialEq, Eq, Clone, Debug)]\n// pub struct ListNode {\n// pub val: i32,\n// pub next: Option<Box<ListNode>>\n// }\n// \n// impl ListNode {\n// #[inline]\n// fn new(val: i32) -> Self {\n// ListNode {\n// next: None,\n// val\n// }\n// }\n// }\nimpl Solution {\n pub fn delete_middle(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {\n \n }\n}",
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"code": "/**\n * Definition for a singly-linked list.\n * class ListNode {\n * public $val = 0;\n * public $next = null;\n * function __construct($val = 0, $next = null) {\n * $this->val = $val;\n * $this->next = $next;\n * }\n * }\n */\nclass Solution {\n\n /**\n * @param ListNode $head\n * @return ListNode\n */\n function deleteMiddle($head) {\n \n }\n}",
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"code": "/**\n * Definition for singly-linked list.\n * class ListNode {\n * val: number\n * next: ListNode | null\n * constructor(val?: number, next?: ListNode | null) {\n * this.val = (val===undefined ? 0 : val)\n * this.next = (next===undefined ? null : next)\n * }\n * }\n */\n\nfunction deleteMiddle(head: ListNode | null): ListNode | null {\n\n};",
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"code": "; Definition for singly-linked list:\n#|\n\n; val : integer?\n; next : (or/c list-node? #f)\n(struct list-node\n (val next) #:mutable #:transparent)\n\n; constructor\n(define (make-list-node [val 0])\n (list-node val #f))\n\n|#\n\n(define/contract (delete-middle head)\n (-> (or/c list-node? #f) (or/c list-node? #f))\n\n )",
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"code": "%% Definition for singly-linked list.\n%%\n%% -record(list_node, {val = 0 :: integer(),\n%% next = null :: 'null' | #list_node{}}).\n\n-spec delete_middle(Head :: #list_node{} | null) -> #list_node{} | null.\ndelete_middle(Head) ->\n .",
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"code": "# Definition for singly-linked list.\n#\n# defmodule ListNode do\n# @type t :: %__MODULE__{\n# val: integer,\n# next: ListNode.t() | nil\n# }\n# defstruct val: 0, next: nil\n# end\n\ndefmodule Solution do\n @spec delete_middle(head :: ListNode.t | nil) :: ListNode.t | nil\n def delete_middle(head) do\n\n end\nend",
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"If a point with a speed s moves n units in a given time, a point with speed 2 * s will move 2 * n units at the same time. Can you use this to find the middle node of a linked list?",
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"If you are given the middle node, the node before it, and the node after it, how can you modify the linked list?"
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