{ "data": { "question": { "questionId": "816", "questionFrontendId": "705", "boundTopicId": null, "title": "Design HashSet", "titleSlug": "design-hashset", "content": "

Design a HashSet without using any built-in hash table libraries.

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Implement MyHashSet class:

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Example 1:

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\nInput\n["MyHashSet", "add", "add", "contains", "contains", "add", "contains", "remove", "contains"]\n[[], [1], [2], [1], [3], [2], [2], [2], [2]]\nOutput\n[null, null, null, true, false, null, true, null, false]\n\nExplanation\nMyHashSet myHashSet = new MyHashSet();\nmyHashSet.add(1);      // set = [1]\nmyHashSet.add(2);      // set = [1, 2]\nmyHashSet.contains(1); // return True\nmyHashSet.contains(3); // return False, (not found)\nmyHashSet.add(2);      // set = [1, 2]\nmyHashSet.contains(2); // return True\nmyHashSet.remove(2);   // set = [1]\nmyHashSet.contains(2); // return False, (already removed)
\n\n

 

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Constraints:

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"translatedName": null, "__typename": "TopicTagNode" }, { "name": "Hash Function", "slug": "hash-function", "translatedName": null, "__typename": "TopicTagNode" } ], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class MyHashSet {\npublic:\n MyHashSet() {\n \n }\n \n void add(int key) {\n \n }\n \n void remove(int key) {\n \n }\n \n bool contains(int key) {\n \n }\n};\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * MyHashSet* obj = new MyHashSet();\n * obj->add(key);\n * obj->remove(key);\n * bool param_3 = obj->contains(key);\n */", "__typename": "CodeSnippetNode" }, { "lang": "Java", "langSlug": "java", "code": "class MyHashSet {\n\n public MyHashSet() {\n \n }\n \n public void add(int key) {\n \n }\n \n public void remove(int key) {\n \n }\n \n public boolean contains(int key) {\n \n }\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * MyHashSet obj = new MyHashSet();\n * obj.add(key);\n * obj.remove(key);\n * boolean param_3 = obj.contains(key);\n */", "__typename": "CodeSnippetNode" }, { "lang": "Python", "langSlug": "python", "code": "class MyHashSet(object):\n\n def __init__(self):\n \n\n def add(self, key):\n \"\"\"\n :type key: int\n :rtype: None\n \"\"\"\n \n\n def remove(self, key):\n \"\"\"\n :type key: int\n :rtype: None\n \"\"\"\n \n\n def contains(self, key):\n \"\"\"\n :type key: int\n :rtype: bool\n \"\"\"\n \n\n\n# Your MyHashSet object will be instantiated and called as such:\n# obj = MyHashSet()\n# obj.add(key)\n# obj.remove(key)\n# param_3 = obj.contains(key)", "__typename": "CodeSnippetNode" }, { "lang": "Python3", "langSlug": "python3", "code": "class MyHashSet:\n\n def __init__(self):\n \n\n def add(self, key: int) -> None:\n \n\n def remove(self, key: int) -> None:\n \n\n def contains(self, key: int) -> bool:\n \n\n\n# Your MyHashSet object will be instantiated and called as such:\n# obj = MyHashSet()\n# obj.add(key)\n# obj.remove(key)\n# param_3 = obj.contains(key)", "__typename": "CodeSnippetNode" }, { "lang": "C", "langSlug": "c", "code": "\n\n\ntypedef struct {\n \n} MyHashSet;\n\n\nMyHashSet* myHashSetCreate() {\n \n}\n\nvoid myHashSetAdd(MyHashSet* obj, int key) {\n \n}\n\nvoid myHashSetRemove(MyHashSet* obj, int key) {\n \n}\n\nbool myHashSetContains(MyHashSet* obj, int key) {\n \n}\n\nvoid myHashSetFree(MyHashSet* obj) {\n \n}\n\n/**\n * Your MyHashSet struct will be instantiated and called as such:\n * MyHashSet* obj = myHashSetCreate();\n * myHashSetAdd(obj, key);\n \n * myHashSetRemove(obj, key);\n \n * bool param_3 = myHashSetContains(obj, key);\n \n * myHashSetFree(obj);\n*/", "__typename": "CodeSnippetNode" }, { "lang": "C#", "langSlug": "csharp", "code": "public class MyHashSet {\n\n public MyHashSet() {\n \n }\n \n public void Add(int key) {\n \n }\n \n public void Remove(int key) {\n \n }\n \n public bool Contains(int key) {\n \n }\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * MyHashSet obj = new MyHashSet();\n * obj.Add(key);\n * obj.Remove(key);\n * bool param_3 = obj.Contains(key);\n */", "__typename": "CodeSnippetNode" }, { "lang": "JavaScript", "langSlug": "javascript", "code": "\nvar MyHashSet = function() {\n \n};\n\n/** \n * @param {number} key\n * @return {void}\n */\nMyHashSet.prototype.add = function(key) {\n \n};\n\n/** \n * @param {number} key\n * @return {void}\n */\nMyHashSet.prototype.remove = function(key) {\n \n};\n\n/** \n * @param {number} key\n * @return {boolean}\n */\nMyHashSet.prototype.contains = function(key) {\n \n};\n\n/** \n * Your MyHashSet object will be instantiated and called as such:\n * var obj = new MyHashSet()\n * obj.add(key)\n * obj.remove(key)\n * var param_3 = obj.contains(key)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Ruby", "langSlug": "ruby", "code": "class MyHashSet\n def initialize()\n \n end\n\n\n=begin\n :type key: Integer\n :rtype: Void\n=end\n def add(key)\n \n end\n\n\n=begin\n :type key: Integer\n :rtype: Void\n=end\n def remove(key)\n \n end\n\n\n=begin\n :type key: Integer\n :rtype: Boolean\n=end\n def contains(key)\n \n end\n\n\nend\n\n# Your MyHashSet object will be instantiated and called as such:\n# obj = MyHashSet.new()\n# obj.add(key)\n# obj.remove(key)\n# param_3 = obj.contains(key)", "__typename": "CodeSnippetNode" }, { "lang": "Swift", "langSlug": "swift", "code": "\nclass MyHashSet {\n\n init() {\n \n }\n \n func add(_ key: Int) {\n \n }\n \n func remove(_ key: Int) {\n \n }\n \n func contains(_ key: Int) -> Bool {\n \n }\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * let obj = MyHashSet()\n * obj.add(key)\n * obj.remove(key)\n * let ret_3: Bool = obj.contains(key)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Go", "langSlug": "golang", "code": "type MyHashSet struct {\n \n}\n\n\nfunc Constructor() MyHashSet {\n \n}\n\n\nfunc (this *MyHashSet) Add(key int) {\n \n}\n\n\nfunc (this *MyHashSet) Remove(key int) {\n \n}\n\n\nfunc (this *MyHashSet) Contains(key int) bool {\n \n}\n\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * obj := Constructor();\n * obj.Add(key);\n * obj.Remove(key);\n * param_3 := obj.Contains(key);\n */", "__typename": "CodeSnippetNode" }, { "lang": "Scala", "langSlug": "scala", "code": "class MyHashSet() {\n\n def add(key: Int) {\n \n }\n\n def remove(key: Int) {\n \n }\n\n def contains(key: Int): Boolean = {\n \n }\n\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * var obj = new MyHashSet()\n * obj.add(key)\n * obj.remove(key)\n * var param_3 = obj.contains(key)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Kotlin", "langSlug": "kotlin", "code": "class MyHashSet() {\n\n fun add(key: Int) {\n \n }\n\n fun remove(key: Int) {\n \n }\n\n fun contains(key: Int): Boolean {\n \n }\n\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * var obj = MyHashSet()\n * obj.add(key)\n * obj.remove(key)\n * var param_3 = obj.contains(key)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Rust", "langSlug": "rust", "code": "struct MyHashSet {\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 MyHashSet {\n\n fn new() -> Self {\n \n }\n \n fn add(&self, key: i32) {\n \n }\n \n fn remove(&self, key: i32) {\n \n }\n \n fn contains(&self, key: i32) -> bool {\n \n }\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * let obj = MyHashSet::new();\n * obj.add(key);\n * obj.remove(key);\n * let ret_3: bool = obj.contains(key);\n */", "__typename": "CodeSnippetNode" }, { "lang": "PHP", "langSlug": "php", "code": "class MyHashSet {\n /**\n */\n function __construct() {\n \n }\n \n /**\n * @param Integer $key\n * @return NULL\n */\n function add($key) {\n \n }\n \n /**\n * @param Integer $key\n * @return NULL\n */\n function remove($key) {\n \n }\n \n /**\n * @param Integer $key\n * @return Boolean\n */\n function contains($key) {\n \n }\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * $obj = MyHashSet();\n * $obj->add($key);\n * $obj->remove($key);\n * $ret_3 = $obj->contains($key);\n */", "__typename": "CodeSnippetNode" }, { "lang": "TypeScript", "langSlug": "typescript", "code": "class MyHashSet {\n constructor() {\n\n }\n\n add(key: number): void {\n\n }\n\n remove(key: number): void {\n\n }\n\n contains(key: number): boolean {\n\n }\n}\n\n/**\n * Your MyHashSet object will be instantiated and called as such:\n * var obj = new MyHashSet()\n * obj.add(key)\n * obj.remove(key)\n * var param_3 = obj.contains(key)\n */", "__typename": "CodeSnippetNode" }, { "lang": "Racket", "langSlug": "racket", "code": "(define my-hash-set%\n (class object%\n (super-new)\n (init-field)\n \n ; add : exact-integer? -> void?\n (define/public (add key)\n\n )\n ; remove : exact-integer? -> void?\n (define/public (remove key)\n\n )\n ; contains : exact-integer? -> boolean?\n (define/public (contains key)\n\n )))\n\n;; Your my-hash-set% object will be instantiated and called as such:\n;; (define obj (new my-hash-set%))\n;; (send obj add key)\n;; (send obj remove key)\n;; (define param_3 (send obj contains key))", "__typename": "CodeSnippetNode" }, { "lang": "Erlang", "langSlug": "erlang", "code": "-spec my_hash_set_init_() -> any().\nmy_hash_set_init_() ->\n .\n\n-spec my_hash_set_add(Key :: integer()) -> any().\nmy_hash_set_add(Key) ->\n .\n\n-spec my_hash_set_remove(Key :: integer()) -> any().\nmy_hash_set_remove(Key) ->\n .\n\n-spec my_hash_set_contains(Key :: integer()) -> boolean().\nmy_hash_set_contains(Key) ->\n .\n\n\n%% Your functions will be called as such:\n%% my_hash_set_init_(),\n%% my_hash_set_add(Key),\n%% my_hash_set_remove(Key),\n%% Param_3 = my_hash_set_contains(Key),\n\n%% my_hash_set_init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" }, { "lang": "Elixir", "langSlug": "elixir", "code": "defmodule MyHashSet do\n @spec init_() :: any\n def init_() do\n\n end\n\n @spec add(key :: integer) :: any\n def add(key) do\n\n end\n\n @spec remove(key :: integer) :: any\n def remove(key) do\n\n end\n\n @spec contains(key :: integer) :: boolean\n def contains(key) do\n\n end\nend\n\n# Your functions will be called as such:\n# MyHashSet.init_()\n# MyHashSet.add(key)\n# MyHashSet.remove(key)\n# param_3 = MyHashSet.contains(key)\n\n# MyHashSet.init_ will be called before every test case, in which you can do some necessary initializations.", "__typename": "CodeSnippetNode" } ], "stats": "{\"totalAccepted\": \"170.2K\", \"totalSubmission\": \"266.9K\", \"totalAcceptedRaw\": 170173, \"totalSubmissionRaw\": 266857, \"acRate\": \"63.8%\"}", "hints": [], "solution": { "id": "852", "canSeeDetail": false, "paidOnly": true, "hasVideoSolution": false, 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\\r\\n

\\r\\n\\r\\n

2. Looking up an item in a hash:\\r\\n

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\\r\\n

\\r\\n\\r\\n

3. Deleting an item in a hash:\\r\\n

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\\r\\n

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