leetcode-problemset/leetcode/originData/swap-nodes-in-pairs.json

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            "title": "Swap Nodes in Pairs",
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            "content": "<p>Given a&nbsp;linked list, swap every two adjacent nodes and return its head. You must solve the problem without&nbsp;modifying the values in the list&#39;s nodes (i.e., only nodes themselves may be changed.)</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2020/10/03/swap_ex1.jpg\" style=\"width: 422px; height: 222px;\" />\n<pre>\n<strong>Input:</strong> head = [1,2,3,4]\n<strong>Output:</strong> [2,1,4,3]\n</pre>\n\n<p><strong>Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> head = []\n<strong>Output:</strong> []\n</pre>\n\n<p><strong>Example 3:</strong></p>\n\n<pre>\n<strong>Input:</strong> head = [1]\n<strong>Output:</strong> [1]\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li>The number of nodes in the&nbsp;list&nbsp;is in the range <code>[0, 100]</code>.</li>\n\t<li><code>0 &lt;= Node.val &lt;= 100</code></li>\n</ul>\n",
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            "difficulty": "Medium",
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                {
                    "name": "Linked List",
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                    "lang": "C++",
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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* swapPairs(ListNode* head) {\n        \n    }\n};",
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                    "lang": "Java",
                    "langSlug": "java",
                    "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 swapPairs(ListNode head) {\n        \n    }\n}",
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                    "lang": "Python",
                    "langSlug": "python",
                    "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 swapPairs(self, head):\n        \"\"\"\n        :type head: ListNode\n        :rtype: ListNode\n        \"\"\"\n        ",
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                {
                    "lang": "Python3",
                    "langSlug": "python3",
                    "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 swapPairs(self, head: Optional[ListNode]) -> Optional[ListNode]:\n        ",
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                    "lang": "C",
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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* swapPairs(struct ListNode* head){\n\n}",
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                    "lang": "C#",
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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 SwapPairs(ListNode head) {\n        \n    }\n}",
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                    "lang": "JavaScript",
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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 swapPairs = function(head) {\n    \n};",
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                    "lang": "Ruby",
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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 swap_pairs(head)\n    \nend",
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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 swapPairs(_ head: ListNode?) -> ListNode? {\n        \n    }\n}",
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                    "lang": "Go",
                    "langSlug": "golang",
                    "code": "/**\n * Definition for singly-linked list.\n * type ListNode struct {\n *     Val int\n *     Next *ListNode\n * }\n */\nfunc swapPairs(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 swapPairs(head: ListNode): ListNode = {\n        \n    }\n}",
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                    "lang": "Kotlin",
                    "langSlug": "kotlin",
                    "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 swapPairs(head: ListNode?): ListNode? {\n        \n    }\n}",
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                    "lang": "Rust",
                    "langSlug": "rust",
                    "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 swap_pairs(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {\n        \n    }\n}",
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                    "lang": "PHP",
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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 $head\n     * @return ListNode\n     */\n    function swapPairs($head) {\n        \n    }\n}",
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                    "lang": "TypeScript",
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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 swapPairs(head: ListNode | null): ListNode | null {\n\n};",
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                    "lang": "Racket",
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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 (swap-pairs head)\n  (-> (or/c list-node? #f) (or/c list-node? #f))\n\n  )",
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                    "lang": "Erlang",
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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 swap_pairs(Head :: #list_node{} | null) -> #list_node{} | null.\nswap_pairs(Head) ->\n  .",
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                    "lang": "Elixir",
                    "langSlug": "elixir",
                    "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 swap_pairs(head :: ListNode.t | nil) :: ListNode.t | nil\n  def swap_pairs(head) do\n\n  end\nend",
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