{ "data": { "question": { "questionId": "381", "questionFrontendId": "381", "boundTopicId": null, "title": "Insert Delete GetRandom O(1) - Duplicates allowed", "titleSlug": "insert-delete-getrandom-o1-duplicates-allowed", "content": "

RandomizedCollection is a data structure that contains a collection of numbers, possibly duplicates (i.e., a multiset). It should support inserting and removing specific elements and also reporting a random element.

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Implement the RandomizedCollection class:

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You must implement the functions of the class such that each function works on average O(1) time complexity.

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Note: The test cases are generated such that getRandom will only be called if there is at least one item in the RandomizedCollection.

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Example 1:

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\nInput\n["RandomizedCollection", "insert", "insert", "insert", "getRandom", "remove", "getRandom"]\n[[], [1], [1], [2], [], [1], []]\nOutput\n[null, true, false, true, 2, true, 1]\n\nExplanation\nRandomizedCollection randomizedCollection = new RandomizedCollection();\nrandomizedCollection.insert(1);   // return true since the collection does not contain 1.\n                                  // Inserts 1 into the collection.\nrandomizedCollection.insert(1);   // return false since the collection contains 1.\n                                  // Inserts another 1 into the collection. Collection now contains [1,1].\nrandomizedCollection.insert(2);   // return true since the collection does not contain 2.\n                                  // Inserts 2 into the collection. Collection now contains [1,1,2].\nrandomizedCollection.getRandom(); // getRandom should:\n                                  // - return 1 with probability 2/3, or\n                                  // - return 2 with probability 1/3.\nrandomizedCollection.remove(1);   // return true since the collection contains 1.\n                                  // Removes 1 from the collection. Collection now contains [1,2].\nrandomizedCollection.getRandom(); // getRandom should return 1 or 2, both equally likely.\n
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Constraints:

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"__typename": "TopicTagNode" } ], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class RandomizedCollection {\npublic:\n RandomizedCollection() {\n \n }\n \n bool insert(int val) {\n \n }\n \n bool remove(int val) {\n \n }\n \n int getRandom() {\n \n }\n};\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * RandomizedCollection* obj = new RandomizedCollection();\n * bool param_1 = obj->insert(val);\n * bool param_2 = obj->remove(val);\n * int param_3 = obj->getRandom();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Java", "langSlug": "java", "code": "class RandomizedCollection {\n\n public RandomizedCollection() {\n \n }\n \n public boolean insert(int val) {\n \n }\n \n public boolean remove(int val) {\n \n }\n \n public int getRandom() {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * RandomizedCollection obj = new RandomizedCollection();\n * boolean param_1 = obj.insert(val);\n * boolean param_2 = obj.remove(val);\n * int param_3 = obj.getRandom();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Python", "langSlug": "python", "code": "class RandomizedCollection(object):\n\n def __init__(self):\n \n\n def insert(self, val):\n \"\"\"\n :type val: int\n :rtype: bool\n \"\"\"\n \n\n def remove(self, val):\n \"\"\"\n :type val: int\n :rtype: bool\n \"\"\"\n \n\n def getRandom(self):\n \"\"\"\n :rtype: int\n \"\"\"\n \n\n\n# Your RandomizedCollection object will be instantiated and called as such:\n# obj = RandomizedCollection()\n# param_1 = obj.insert(val)\n# param_2 = obj.remove(val)\n# param_3 = obj.getRandom()", "__typename": "CodeSnippetNode" }, { "lang": "Python3", "langSlug": "python3", "code": "class RandomizedCollection:\n\n def __init__(self):\n \n\n def insert(self, val: int) -> bool:\n \n\n def remove(self, val: int) -> bool:\n \n\n def getRandom(self) -> int:\n \n\n\n# Your RandomizedCollection object will be instantiated and called as such:\n# obj = RandomizedCollection()\n# param_1 = obj.insert(val)\n# param_2 = obj.remove(val)\n# param_3 = obj.getRandom()", "__typename": "CodeSnippetNode" }, { "lang": "C", "langSlug": "c", "code": "\n\n\ntypedef struct {\n \n} RandomizedCollection;\n\n\nRandomizedCollection* randomizedCollectionCreate() {\n \n}\n\nbool randomizedCollectionInsert(RandomizedCollection* obj, int val) {\n \n}\n\nbool randomizedCollectionRemove(RandomizedCollection* obj, int val) {\n \n}\n\nint randomizedCollectionGetRandom(RandomizedCollection* obj) {\n \n}\n\nvoid randomizedCollectionFree(RandomizedCollection* obj) {\n \n}\n\n/**\n * Your RandomizedCollection struct will be instantiated and called as such:\n * RandomizedCollection* obj = randomizedCollectionCreate();\n * bool param_1 = randomizedCollectionInsert(obj, val);\n \n * bool param_2 = randomizedCollectionRemove(obj, val);\n \n * int param_3 = randomizedCollectionGetRandom(obj);\n \n * randomizedCollectionFree(obj);\n*/", "__typename": "CodeSnippetNode" }, { "lang": "C#", "langSlug": "csharp", "code": "public class RandomizedCollection {\n\n public RandomizedCollection() {\n \n }\n \n public bool Insert(int val) {\n \n }\n \n public bool Remove(int val) {\n \n }\n \n public int GetRandom() {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * RandomizedCollection obj = new RandomizedCollection();\n * bool param_1 = obj.Insert(val);\n * bool param_2 = obj.Remove(val);\n * int param_3 = obj.GetRandom();\n */", "__typename": "CodeSnippetNode" }, { "lang": "JavaScript", "langSlug": "javascript", "code": "\nvar RandomizedCollection = function() {\n \n};\n\n/** \n * @param {number} val\n * @return {boolean}\n */\nRandomizedCollection.prototype.insert = function(val) {\n \n};\n\n/** \n * @param {number} val\n * @return {boolean}\n */\nRandomizedCollection.prototype.remove = function(val) {\n \n};\n\n/**\n * @return {number}\n */\nRandomizedCollection.prototype.getRandom = function() {\n \n};\n\n/** \n * Your RandomizedCollection object will be instantiated and called as such:\n * var obj = new RandomizedCollection()\n * var param_1 = obj.insert(val)\n * var param_2 = obj.remove(val)\n * var param_3 = obj.getRandom()\n */", "__typename": "CodeSnippetNode" }, { "lang": "TypeScript", "langSlug": "typescript", "code": "class RandomizedCollection {\n constructor() {\n \n }\n\n insert(val: number): boolean {\n \n }\n\n remove(val: number): boolean {\n \n }\n\n getRandom(): number {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * var obj = new RandomizedCollection()\n * var param_1 = obj.insert(val)\n * var param_2 = obj.remove(val)\n * var param_3 = obj.getRandom()\n */", "__typename": "CodeSnippetNode" }, { "lang": "PHP", "langSlug": "php", "code": "class RandomizedCollection {\n /**\n */\n function __construct() {\n \n }\n \n /**\n * @param Integer $val\n * @return Boolean\n */\n function insert($val) {\n \n }\n \n /**\n * @param Integer $val\n * @return Boolean\n */\n function remove($val) {\n \n }\n \n /**\n * @return Integer\n */\n function getRandom() {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * $obj = RandomizedCollection();\n * $ret_1 = $obj->insert($val);\n * $ret_2 = $obj->remove($val);\n * $ret_3 = $obj->getRandom();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Swift", "langSlug": "swift", "code": "\nclass RandomizedCollection {\n\n init() {\n \n }\n \n func insert(_ val: Int) -> Bool {\n \n }\n \n func remove(_ val: Int) -> Bool {\n \n }\n \n func getRandom() -> Int {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * let obj = RandomizedCollection()\n * let ret_1: Bool = obj.insert(val)\n * let ret_2: Bool = obj.remove(val)\n * let ret_3: Int = obj.getRandom()\n */", "__typename": "CodeSnippetNode" }, { "lang": "Kotlin", "langSlug": "kotlin", "code": "class RandomizedCollection() {\n\n fun insert(`val`: Int): Boolean {\n \n }\n\n fun remove(`val`: Int): Boolean {\n \n }\n\n fun getRandom(): Int {\n \n }\n\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * var obj = RandomizedCollection()\n * var param_1 = obj.insert(`val`)\n * var param_2 = obj.remove(`val`)\n * var param_3 = obj.getRandom()\n */", "__typename": "CodeSnippetNode" }, { "lang": "Dart", "langSlug": "dart", "code": "class RandomizedCollection {\n\n RandomizedCollection() {\n \n }\n \n bool insert(int val) {\n \n }\n \n bool remove(int val) {\n \n }\n \n int getRandom() {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * RandomizedCollection obj = RandomizedCollection();\n * bool param1 = obj.insert(val);\n * bool param2 = obj.remove(val);\n * int param3 = obj.getRandom();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Go", "langSlug": "golang", "code": "type RandomizedCollection struct {\n \n}\n\n\nfunc Constructor() RandomizedCollection {\n \n}\n\n\nfunc (this *RandomizedCollection) Insert(val int) bool {\n \n}\n\n\nfunc (this *RandomizedCollection) Remove(val int) bool {\n \n}\n\n\nfunc (this *RandomizedCollection) GetRandom() int {\n \n}\n\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * obj := Constructor();\n * param_1 := obj.Insert(val);\n * param_2 := obj.Remove(val);\n * param_3 := obj.GetRandom();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Ruby", "langSlug": "ruby", "code": "class RandomizedCollection\n def initialize()\n \n end\n\n\n=begin\n :type val: Integer\n :rtype: Boolean\n=end\n def insert(val)\n \n end\n\n\n=begin\n :type val: Integer\n :rtype: Boolean\n=end\n def remove(val)\n \n end\n\n\n=begin\n :rtype: Integer\n=end\n def get_random()\n \n end\n\n\nend\n\n# Your RandomizedCollection object will be instantiated and called as such:\n# obj = RandomizedCollection.new()\n# param_1 = obj.insert(val)\n# param_2 = obj.remove(val)\n# param_3 = obj.get_random()", "__typename": "CodeSnippetNode" }, { "lang": "Scala", "langSlug": "scala", "code": "class RandomizedCollection() {\n\n def insert(`val`: Int): Boolean = {\n \n }\n\n def remove(`val`: Int): Boolean = {\n \n }\n\n def getRandom(): Int = {\n \n }\n\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * var obj = new RandomizedCollection()\n * var param_1 = obj.insert(`val`)\n * var param_2 = obj.remove(`val`)\n * var param_3 = obj.getRandom()\n */", "__typename": "CodeSnippetNode" }, { "lang": "Rust", "langSlug": "rust", "code": "struct RandomizedCollection {\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 RandomizedCollection {\n\n fn new() -> Self {\n \n }\n \n fn insert(&self, val: i32) -> bool {\n \n }\n \n fn remove(&self, val: i32) -> bool {\n \n }\n \n fn get_random(&self) -> i32 {\n \n }\n}\n\n/**\n * Your RandomizedCollection object will be instantiated and called as such:\n * let obj = RandomizedCollection::new();\n * let ret_1: bool = obj.insert(val);\n * let ret_2: bool = obj.remove(val);\n * let ret_3: i32 = obj.get_random();\n */", "__typename": "CodeSnippetNode" }, { "lang": "Racket", "langSlug": "racket", "code": "(define randomized-collection%\n (class object%\n (super-new)\n \n (init-field)\n \n ; insert : exact-integer? -> boolean?\n (define/public (insert val)\n )\n ; remove : exact-integer? -> boolean?\n (define/public (remove val)\n )\n ; get-random : -> exact-integer?\n (define/public (get-random)\n )))\n\n;; Your randomized-collection% object will be instantiated and called as such:\n;; (define obj (new randomized-collection%))\n;; (define param_1 (send obj insert val))\n;; (define param_2 (send obj remove val))\n;; (define param_3 (send obj get-random))", "__typename": "CodeSnippetNode" }, { "lang": "Erlang", "langSlug": "erlang", "code": "-spec randomized_collection_init_() -> any().\nrandomized_collection_init_() ->\n .\n\n-spec randomized_collection_insert(Val :: integer()) -> boolean().\nrandomized_collection_insert(Val) ->\n .\n\n-spec randomized_collection_remove(Val :: integer()) -> boolean().\nrandomized_collection_remove(Val) ->\n .\n\n-spec randomized_collection_get_random() -> integer().\nrandomized_collection_get_random() ->\n .\n\n\n%% Your functions will be called as such:\n%% randomized_collection_init_(),\n%% Param_1 = randomized_collection_insert(Val),\n%% Param_2 = randomized_collection_remove(Val),\n%% Param_3 = randomized_collection_get_random(),\n\n%% randomized_collection_init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" }, { "lang": "Elixir", "langSlug": "elixir", "code": "defmodule RandomizedCollection do\n @spec init_() :: any\n def init_() do\n 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