Shuffle an Array
<p>Given an integer array <code>nums</code>, design an algorithm to randomly shuffle the array. All permutations of the array should be <strong>equally likely</strong> as a result of the shuffling.</p>

<p>Implement the <code>Solution</code> class:</p>

<ul>
	<li><code>Solution(int[] nums)</code> Initializes the object with the integer array <code>nums</code>.</li>
	<li><code>int[] reset()</code> Resets the array to its original configuration and returns it.</li>
	<li><code>int[] shuffle()</code> Returns a random shuffling of the array.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input</strong>
[&quot;Solution&quot;, &quot;shuffle&quot;, &quot;reset&quot;, &quot;shuffle&quot;]
[[[1, 2, 3]], [], [], []]
<strong>Output</strong>
[null, [3, 1, 2], [1, 2, 3], [1, 3, 2]]

<strong>Explanation</strong>
Solution solution = new Solution([1, 2, 3]);
solution.shuffle();    // Shuffle the array [1,2,3] and return its result.
                       // Any permutation of [1,2,3] must be equally likely to be returned.
                       // Example: return [3, 1, 2]
solution.reset();      // Resets the array back to its original configuration [1,2,3]. Return [1, 2, 3]
solution.shuffle();    // Returns the random shuffling of array [1,2,3]. Example: return [1, 3, 2]

</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 50</code></li>
	<li><code>-10<sup>6</sup> &lt;= nums[i] &lt;= 10<sup>6</sup></code></li>
	<li>All the elements of <code>nums</code> are <strong>unique</strong>.</li>
	<li>At most <code>10<sup>4</sup></code> calls <strong>in total</strong> will be made to <code>reset</code> and <code>shuffle</code>.</li>
</ul>

[]
[]
[{"value": "cpp", "text": "C++", "defaultCode": "class Solution {\npublic:\n    Solution(vector<int>& nums) {\n        \n    }\n    \n    vector<int> reset() {\n        \n    }\n    \n    vector<int> shuffle() {\n        \n    }\n};\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution* obj = new Solution(nums);\n * vector<int> param_1 = obj->reset();\n * vector<int> param_2 = obj->shuffle();\n */"}, {"value": "java", "text": "Java", "defaultCode": "class Solution {\n\n    public Solution(int[] nums) {\n        \n    }\n    \n    public int[] reset() {\n        \n    }\n    \n    public int[] shuffle() {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution obj = new Solution(nums);\n * int[] param_1 = obj.reset();\n * int[] param_2 = obj.shuffle();\n */"}, {"value": "python", "text": "Python", "defaultCode": "class Solution(object):\n\n    def __init__(self, nums):\n        \"\"\"\n        :type nums: List[int]\n        \"\"\"\n        \n\n    def reset(self):\n        \"\"\"\n        :rtype: List[int]\n        \"\"\"\n        \n\n    def shuffle(self):\n        \"\"\"\n        :rtype: List[int]\n        \"\"\"\n        \n\n\n# Your Solution object will be instantiated and called as such:\n# obj = Solution(nums)\n# param_1 = obj.reset()\n# param_2 = obj.shuffle()"}, {"value": "python3", "text": "Python3", "defaultCode": "class Solution:\n\n    def __init__(self, nums: List[int]):\n        \n\n    def reset(self) -> List[int]:\n        \n\n    def shuffle(self) -> List[int]:\n        \n\n\n# Your Solution object will be instantiated and called as such:\n# obj = Solution(nums)\n# param_1 = obj.reset()\n# param_2 = obj.shuffle()"}, {"value": "c", "text": "C", "defaultCode": "\n\n\ntypedef struct {\n    \n} Solution;\n\n\nSolution* solutionCreate(int* nums, int numsSize) {\n    \n}\n\nint* solutionReset(Solution* obj, int* retSize) {\n    \n}\n\nint* solutionShuffle(Solution* obj, int* retSize) {\n    \n}\n\nvoid solutionFree(Solution* obj) {\n    \n}\n\n/**\n * Your Solution struct will be instantiated and called as such:\n * Solution* obj = solutionCreate(nums, numsSize);\n * int* param_1 = solutionReset(obj, retSize);\n \n * int* param_2 = solutionShuffle(obj, retSize);\n \n * solutionFree(obj);\n*/"}, {"value": "csharp", "text": "C#", "defaultCode": "public class Solution {\n\n    public Solution(int[] nums) {\n        \n    }\n    \n    public int[] Reset() {\n        \n    }\n    \n    public int[] Shuffle() {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution obj = new Solution(nums);\n * int[] param_1 = obj.Reset();\n * int[] param_2 = obj.Shuffle();\n */"}, {"value": "javascript", "text": "JavaScript", "defaultCode": "/**\n * @param {number[]} nums\n */\nvar Solution = function(nums) {\n    \n};\n\n/**\n * @return {number[]}\n */\nSolution.prototype.reset = function() {\n    \n};\n\n/**\n * @return {number[]}\n */\nSolution.prototype.shuffle = function() {\n    \n};\n\n/** \n * Your Solution object will be instantiated and called as such:\n * var obj = new Solution(nums)\n * var param_1 = obj.reset()\n * var param_2 = obj.shuffle()\n */"}, {"value": "typescript", "text": "TypeScript", "defaultCode": "class Solution {\n    constructor(nums: number[]) {\n        \n    }\n\n    reset(): number[] {\n        \n    }\n\n    shuffle(): number[] {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * var obj = new Solution(nums)\n * var param_1 = obj.reset()\n * var param_2 = obj.shuffle()\n */"}, {"value": "php", "text": "PHP", "defaultCode": "class Solution {\n    /**\n     * @param Integer[] $nums\n     */\n    function __construct($nums) {\n        \n    }\n  \n    /**\n     * @return Integer[]\n     */\n    function reset() {\n        \n    }\n  \n    /**\n     * @return Integer[]\n     */\n    function shuffle() {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * $obj = Solution($nums);\n * $ret_1 = $obj->reset();\n * $ret_2 = $obj->shuffle();\n */"}, {"value": "swift", "text": "Swift", "defaultCode": "\nclass Solution {\n\n    init(_ nums: [Int]) {\n        \n    }\n    \n    func reset() -> [Int] {\n        \n    }\n    \n    func shuffle() -> [Int] {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * let obj = Solution(nums)\n * let ret_1: [Int] = obj.reset()\n * let ret_2: [Int] = obj.shuffle()\n */"}, {"value": "kotlin", "text": "Kotlin", "defaultCode": "class Solution(nums: IntArray) {\n\n    fun reset(): IntArray {\n        \n    }\n\n    fun shuffle(): IntArray {\n        \n    }\n\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * var obj = Solution(nums)\n * var param_1 = obj.reset()\n * var param_2 = obj.shuffle()\n */"}, {"value": "dart", "text": "Dart", "defaultCode": "class Solution {\n\n  Solution(List<int> nums) {\n    \n  }\n  \n  List<int> reset() {\n    \n  }\n  \n  List<int> shuffle() {\n    \n  }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * Solution obj = Solution(nums);\n * List<int> param1 = obj.reset();\n * List<int> param2 = obj.shuffle();\n */"}, {"value": "golang", "text": "Go", "defaultCode": "type Solution struct {\n    \n}\n\n\nfunc Constructor(nums []int) Solution {\n    \n}\n\n\nfunc (this *Solution) Reset() []int {\n    \n}\n\n\nfunc (this *Solution) Shuffle() []int {\n    \n}\n\n\n/**\n * Your Solution object will be instantiated and called as such:\n * obj := Constructor(nums);\n * param_1 := obj.Reset();\n * param_2 := obj.Shuffle();\n */"}, {"value": "ruby", "text": "Ruby", "defaultCode": "class Solution\n\n=begin\n    :type nums: Integer[]\n=end\n    def initialize(nums)\n        \n    end\n\n\n=begin\n    :rtype: Integer[]\n=end\n    def reset()\n        \n    end\n\n\n=begin\n    :rtype: Integer[]\n=end\n    def shuffle()\n        \n    end\n\n\nend\n\n# Your Solution object will be instantiated and called as such:\n# obj = Solution.new(nums)\n# param_1 = obj.reset()\n# param_2 = obj.shuffle()"}, {"value": "scala", "text": "Scala", "defaultCode": "class Solution(_nums: Array[Int]) {\n\n    def reset(): Array[Int] = {\n        \n    }\n\n    def shuffle(): Array[Int] = {\n        \n    }\n\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * val obj = new Solution(nums)\n * val param_1 = obj.reset()\n * val param_2 = obj.shuffle()\n */"}, {"value": "rust", "text": "Rust", "defaultCode": "struct Solution {\n\n}\n\n\n/** \n * `&self` means the method takes an immutable reference.\n * If you need a mutable reference, change it to `&mut self` instead.\n */\nimpl Solution {\n\n    fn new(nums: Vec<i32>) -> Self {\n        \n    }\n    \n    fn reset(&self) -> Vec<i32> {\n        \n    }\n    \n    fn shuffle(&self) -> Vec<i32> {\n        \n    }\n}\n\n/**\n * Your Solution object will be instantiated and called as such:\n * let obj = Solution::new(nums);\n * let ret_1: Vec<i32> = obj.reset();\n * let ret_2: Vec<i32> = obj.shuffle();\n */"}, {"value": "racket", "text": "Racket", "defaultCode": "(define solution%\n  (class object%\n    (super-new)\n    \n    ; nums : (listof exact-integer?)\n    (init-field\n      nums)\n    \n    ; reset : -> (listof exact-integer?)\n    (define/public (reset)\n      )\n    ; shuffle : -> (listof exact-integer?)\n    (define/public (shuffle)\n      )))\n\n;; Your solution% object will be instantiated and called as such:\n;; (define obj (new solution% [nums nums]))\n;; (define param_1 (send obj reset))\n;; (define param_2 (send obj shuffle))"}, {"value": "erlang", "text": "Erlang", "defaultCode": "-spec solution_init_(Nums :: [integer()]) -> any().\nsolution_init_(Nums) ->\n  .\n\n-spec solution_reset() -> [integer()].\nsolution_reset() ->\n  .\n\n-spec solution_shuffle() -> [integer()].\nsolution_shuffle() ->\n  .\n\n\n%% Your functions will be called as such:\n%% solution_init_(Nums),\n%% Param_1 = solution_reset(),\n%% Param_2 = solution_shuffle(),\n\n%% solution_init_ will be called before every test case, in which you can do some necessary initializations."}, {"value": "elixir", "text": "Elixir", "defaultCode": "defmodule Solution do\n  @spec init_(nums :: [integer]) :: any\n  def init_(nums) do\n    \n  end\n\n  @spec reset() :: [integer]\n  def reset() do\n    \n  end\n\n  @spec shuffle() :: [integer]\n  def shuffle() do\n    \n  end\nend\n\n# Your functions will be called as such:\n# Solution.init_(nums)\n# param_1 = Solution.reset()\n# param_2 = Solution.shuffle()\n\n# Solution.init_ will be called before every test case, in which you can do some necessary initializations."}]
{
  "classname": "Solution",
  "constructor": {
    "params": [
      {
        "type": "integer[]",
        "name": "nums"
      }
    ]
  },
  "methods": [
    {
      "params": [],
      "name": "reset",
      "return": {
        "type": "integer[]"
      }
    },
    {
      "params": [],
      "return": {
        "type": "integer[]"
      },
      "name": "shuffle"
    }
  ],
  "return": {
    "type": "boolean"
  },
  "systemdesign": true
}
{"cpp": ["C++", "<p>Compiled with <code> clang 19 </code> using the latest C++ 23 standard, and <code>libstdc++</code> provided by GCC 14.</p>\r\n\r\n<p>Your code is compiled with level two optimization (<code>-O2</code>). <a href=\"https://github.com/google/sanitizers/wiki/AddressSanitizer\" target=\"_blank\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\r\n\r\n<p>Most standard library headers are already included automatically for your convenience.</p>"], "java": ["Java", "<p><code>OpenJDK 21</code>. Using compile arguments: <code>--enable-preview --release 21</code></p>\r\n\r\n<p>Most standard library headers are already included automatically for your convenience.</p>\r\n<p>Includes <code>Pair</code> class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.</p>"], "python": ["Python", "<p><code>Python 2.7.18</code>.</p>\r\n\r\n<p>Most libraries are already imported automatically for your convenience, such as <a href=\"https://docs.python.org/2/library/array.html\" target=\"_blank\">array</a>, <a href=\"https://docs.python.org/2/library/bisect.html\" target=\"_blank\">bisect</a>, <a href=\"https://docs.python.org/2/library/collections.html\" target=\"_blank\">collections</a>. If you need more libraries, you can import it yourself.</p>\r\n\r\n<p>For Map/TreeMap data structure, you may use <a href=\"http://www.grantjenks.com/docs/sortedcontainers/\" target=\"_blank\">sortedcontainers</a> library.</p>\r\n\r\n<p>Note that Python 2.7 <a href=\"https://www.python.org/dev/peps/pep-0373/\" target=\"_blank\">is not maintained anymore</a>. For the latest Python, please choose Python3 instead.</p>"], "c": ["C", "<p>Compiled with <code>gcc 14</code> using the gnu11 standard.</p>\r\n\r\n<p>Your code is compiled with level one optimization (<code>-O2</code>). <a href=\"https://github.com/google/sanitizers/wiki/AddressSanitizer\" target=\"_blank\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\r\n\r\n<p>Most standard library headers are already included automatically for your convenience.</p>\r\n\r\n<p>For hash table operations, you may use <a href=\"https://troydhanson.github.io/uthash/\" target=\"_blank\">uthash</a>. \"uthash.h\" is included by default. Below are some examples:</p>\r\n\r\n<p><b>1. Adding an item to a hash.</b>\r\n<pre>\r\nstruct hash_entry {\r\n    int id;            /* we'll use this field as the key */\r\n    char name[10];\r\n    UT_hash_handle hh; /* makes this structure hashable */\r\n};\r\n\r\nstruct hash_entry *users = NULL;\r\n\r\nvoid add_user(struct hash_entry *s) {\r\n    HASH_ADD_INT(users, id, s);\r\n}\r\n</pre>\r\n</p>\r\n\r\n<p><b>2. Looking up an item in a hash:</b>\r\n<pre>\r\nstruct hash_entry *find_user(int user_id) {\r\n    struct hash_entry *s;\r\n    HASH_FIND_INT(users, &user_id, s);\r\n    return s;\r\n}\r\n</pre>\r\n</p>\r\n\r\n<p><b>3. Deleting an item in a hash:</b>\r\n<pre>\r\nvoid delete_user(struct hash_entry *user) {\r\n    HASH_DEL(users, user);  \r\n}\r\n</pre>\r\n</p>"], "csharp": ["C#", "<p><a href=\"https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-13\" target=\"_blank\">C# 13</a> with .NET 9 runtime</p>"], "javascript": ["JavaScript", "<p><code>Node.js 22.14.0</code>.</p>\r\n\r\n<p>Your code is run with <code>--harmony</code> flag, enabling <a href=\"http://node.green/\" target=\"_blank\">new ES6 features</a>.</p>\r\n\r\n<p><a href=\"https://lodash.com\" target=\"_blank\">lodash.js</a> library is included by default.</p>\r\n\r\n<p>For Priority Queue / Queue data structures, you may use 6.3.2 version of <a href=\"https://github.com/datastructures-js/priority-queue/tree/v6.3.2\" target=\"_blank\">datastructures-js/priority-queue</a> and 4.2.3 version of <a href=\"https://github.com/datastructures-js/queue/tree/v4.2.3\" target=\"_blank\">datastructures-js/queue</a> and 1.0.4 version of <a href=\"https://github.com/datastructures-js/deque/tree/v1.0.4\" target=\"_blank\">datastructures-js/deque</a>.</p>"], "ruby": ["Ruby", "<p><code>Ruby 3.2</code></p>\r\n\r\n<p>Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms</p>"], "swift": ["Swift", "<p><code>Swift 6.0</code>.</p>\r\n\r\n<p>You may use the following packages:<br/>\r\n<a href=\"https://github.com/apple/swift-algorithms/tree/1.2.0\" target=\"_blank\">swift-algorithms 1.2.0</a><br/>\r\n<a href=\"https://github.com/apple/swift-collections/tree/1.1.4\" target=\"_blank\">swift-collections 1.1.4</a><br/>\r\n<a href=\"https://github.com/apple/swift-numerics/tree/1.0.2\" target=\"_blank\">swift-numerics 1.0.2</a></p>"], "golang": ["Go", "<p><code>Go 1.23</code></p>\r\n<p>Support <a href=\"https://pkg.go.dev/github.com/emirpasic/gods@v1.18.1\" target=\"_blank\">https://pkg.go.dev/github.com/emirpasic/gods@v1.18.1</a> and <a href=\"https://pkg.go.dev/github.com/emirpasic/gods/v2@v2.0.0-alpha\" target=\"_blank\">https://pkg.go.dev/github.com/emirpasic/gods/v2@v2.0.0-alpha</a> library.</p>"], "python3": ["Python3", "<p><code>Python 3.11</code>.</p>\r\n\r\n<p>Most libraries are already imported automatically for your convenience, such as <a href=\"https://docs.python.org/3/library/array.html\" target=\"_blank\">array</a>, <a href=\"https://docs.python.org/3/library/bisect.html\" target=\"_blank\">bisect</a>, <a href=\"https://docs.python.org/3/library/collections.html\" target=\"_blank\">collections</a>. If you need more libraries, you can import it yourself.</p>\r\n\r\n<p>For Map/TreeMap data structure, you may use <a href=\"http://www.grantjenks.com/docs/sortedcontainers/\" target=\"_blank\">sortedcontainers</a> library.</p>"], "scala": ["Scala", "<p><code>Scala 3.3.1</code>.</p>"], "kotlin": ["Kotlin", "<p><code>Kotlin 2.1.10</code>.</p>"], "rust": ["Rust", "<p><code>Rust 1.85.0</code>. Your code will be compiled with <code>opt-level</code> 2.</p>\r\n\r\n<p>Supports <a href=\"https://crates.io/crates/rand\" target=\"_blank\">rand v0.8</a> and <a href=\"https://crates.io/crates/regex\" target=\"_blank\">regex\u00a0v1</a> and <a href=\"https://crates.io/crates/itertools\" target=\"_blank\">itertools\u00a0v0.14</a> from crates.io</p>"], "php": ["PHP", "<p><code>PHP 8.2</code>.</p>\r\n<p>With bcmath module</p>"], "typescript": ["Typescript", "<p><code>TypeScript 5.7.3, Node.js 22.14.0</code>.</p>\r\n\r\n<p>Compile Options: <code>--alwaysStrict --strictBindCallApply --strictFunctionTypes --target ES2024</code></p>\r\n\r\n<p><a href=\"https://lodash.com\" target=\"_blank\">lodash.js</a> library is included by default.</p>\r\n\r\n<p>For Priority Queue / Queue data structures, you may use 6.3.2 version of <a href=\"https://github.com/datastructures-js/priority-queue/tree/v6.3.2\" target=\"_blank\">datastructures-js/priority-queue</a> and 4.2.3 version of <a href=\"https://github.com/datastructures-js/queue/tree/v4.2.3\" target=\"_blank\">datastructures-js/queue</a> and 1.0.4 version of <a href=\"https://github.com/datastructures-js/deque/tree/v1.0.4\" target=\"_blank\">datastructures-js/deque</a>.</p>"], "racket": ["Racket", "<p><a href=\"https://docs.racket-lang.org/guide/performance.html#%28tech._c%29\" target=\"_blank\">Racket CS</a> v8.15</p>\r\n\r\n<p>Using <code>#lang racket</code></p>\r\n\r\n<p>Required <code>data/gvector data/queue data/order data/heap</code> automatically for your convenience</p>"], "erlang": ["Erlang", "Erlang/OTP 26"], "elixir": ["Elixir", "Elixir 1.17 with Erlang/OTP 26"], "dart": ["Dart", "<p>Dart 3.2. You may use package <a href=\"https://pub.dev/packages/collection/versions/1.18.0\" target=\"_blank\">collection</a></p>\r\n\r\n<p>Your code will be run directly without compiling</p>"]}
['Array', 'Math', 'Design', 'Randomized']