Time Based Key-Value Store
<p>Design a time-based key-value data structure that can store multiple values for the same key at different time stamps and retrieve the key&#39;s value at a certain timestamp.</p>

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

<ul>
	<li><code>TimeMap()</code> Initializes the object of the data structure.</li>
	<li><code>void set(String key, String value, int timestamp)</code> Stores the key <code>key</code> with the value <code>value</code> at the given time <code>timestamp</code>.</li>
	<li><code>String get(String key, int timestamp)</code> Returns a value such that <code>set</code> was called previously, with <code>timestamp_prev &lt;= timestamp</code>. If there are multiple such values, it returns the value associated with the largest <code>timestamp_prev</code>. If there are no values, it returns <code>&quot;&quot;</code>.</li>
</ul>

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

<pre>
<strong>Input</strong>
[&quot;TimeMap&quot;, &quot;set&quot;, &quot;get&quot;, &quot;get&quot;, &quot;set&quot;, &quot;get&quot;, &quot;get&quot;]
[[], [&quot;foo&quot;, &quot;bar&quot;, 1], [&quot;foo&quot;, 1], [&quot;foo&quot;, 3], [&quot;foo&quot;, &quot;bar2&quot;, 4], [&quot;foo&quot;, 4], [&quot;foo&quot;, 5]]
<strong>Output</strong>
[null, null, &quot;bar&quot;, &quot;bar&quot;, null, &quot;bar2&quot;, &quot;bar2&quot;]

<strong>Explanation</strong>
TimeMap timeMap = new TimeMap();
timeMap.set(&quot;foo&quot;, &quot;bar&quot;, 1);  // store the key &quot;foo&quot; and value &quot;bar&quot; along with timestamp = 1.
timeMap.get(&quot;foo&quot;, 1);         // return &quot;bar&quot;
timeMap.get(&quot;foo&quot;, 3);         // return &quot;bar&quot;, since there is no value corresponding to foo at timestamp 3 and timestamp 2, then the only value is at timestamp 1 is &quot;bar&quot;.
timeMap.set(&quot;foo&quot;, &quot;bar2&quot;, 4); // store the key &quot;foo&quot; and value &quot;bar2&quot; along with timestamp = 4.
timeMap.get(&quot;foo&quot;, 4);         // return &quot;bar2&quot;
timeMap.get(&quot;foo&quot;, 5);         // return &quot;bar2&quot;
</pre>

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

<ul>
	<li><code>1 &lt;= key.length, value.length &lt;= 100</code></li>
	<li><code>key</code> and <code>value</code> consist of lowercase English letters and digits.</li>
	<li><code>1 &lt;= timestamp &lt;= 10<sup>7</sup></code></li>
	<li>All the timestamps <code>timestamp</code> of <code>set</code> are strictly increasing.</li>
	<li>At most <code>2 * 10<sup>5</sup></code> calls will be made to <code>set</code> and <code>get</code>.</li>
</ul>

['stock-price-fluctuation']
[]
[{"value": "cpp", "text": "C++", "defaultCode": "class TimeMap {\npublic:\n    TimeMap() {\n        \n    }\n    \n    void set(string key, string value, int timestamp) {\n        \n    }\n    \n    string get(string key, int timestamp) {\n        \n    }\n};\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * TimeMap* obj = new TimeMap();\n * obj->set(key,value,timestamp);\n * string param_2 = obj->get(key,timestamp);\n */"}, {"value": "java", "text": "Java", "defaultCode": "class TimeMap {\n\n    public TimeMap() {\n        \n    }\n    \n    public void set(String key, String value, int timestamp) {\n        \n    }\n    \n    public String get(String key, int timestamp) {\n        \n    }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * TimeMap obj = new TimeMap();\n * obj.set(key,value,timestamp);\n * String param_2 = obj.get(key,timestamp);\n */"}, {"value": "python", "text": "Python", "defaultCode": "class TimeMap(object):\n\n    def __init__(self):\n        \n\n    def set(self, key, value, timestamp):\n        \"\"\"\n        :type key: str\n        :type value: str\n        :type timestamp: int\n        :rtype: None\n        \"\"\"\n        \n\n    def get(self, key, timestamp):\n        \"\"\"\n        :type key: str\n        :type timestamp: int\n        :rtype: str\n        \"\"\"\n        \n\n\n# Your TimeMap object will be instantiated and called as such:\n# obj = TimeMap()\n# obj.set(key,value,timestamp)\n# param_2 = obj.get(key,timestamp)"}, {"value": "python3", "text": "Python3", "defaultCode": "class TimeMap:\n\n    def __init__(self):\n        \n\n    def set(self, key: str, value: str, timestamp: int) -> None:\n        \n\n    def get(self, key: str, timestamp: int) -> str:\n        \n\n\n# Your TimeMap object will be instantiated and called as such:\n# obj = TimeMap()\n# obj.set(key,value,timestamp)\n# param_2 = obj.get(key,timestamp)"}, {"value": "c", "text": "C", "defaultCode": "\n\n\ntypedef struct {\n    \n} TimeMap;\n\n\nTimeMap* timeMapCreate() {\n    \n}\n\nvoid timeMapSet(TimeMap* obj, char* key, char* value, int timestamp) {\n    \n}\n\nchar* timeMapGet(TimeMap* obj, char* key, int timestamp) {\n    \n}\n\nvoid timeMapFree(TimeMap* obj) {\n    \n}\n\n/**\n * Your TimeMap struct will be instantiated and called as such:\n * TimeMap* obj = timeMapCreate();\n * timeMapSet(obj, key, value, timestamp);\n \n * char* param_2 = timeMapGet(obj, key, timestamp);\n \n * timeMapFree(obj);\n*/"}, {"value": "csharp", "text": "C#", "defaultCode": "public class TimeMap {\n\n    public TimeMap() {\n        \n    }\n    \n    public void Set(string key, string value, int timestamp) {\n        \n    }\n    \n    public string Get(string key, int timestamp) {\n        \n    }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * TimeMap obj = new TimeMap();\n * obj.Set(key,value,timestamp);\n * string param_2 = obj.Get(key,timestamp);\n */"}, {"value": "javascript", "text": "JavaScript", "defaultCode": "\nvar TimeMap = function() {\n    \n};\n\n/** \n * @param {string} key \n * @param {string} value \n * @param {number} timestamp\n * @return {void}\n */\nTimeMap.prototype.set = function(key, value, timestamp) {\n    \n};\n\n/** \n * @param {string} key \n * @param {number} timestamp\n * @return {string}\n */\nTimeMap.prototype.get = function(key, timestamp) {\n    \n};\n\n/** \n * Your TimeMap object will be instantiated and called as such:\n * var obj = new TimeMap()\n * obj.set(key,value,timestamp)\n * var param_2 = obj.get(key,timestamp)\n */"}, {"value": "typescript", "text": "TypeScript", "defaultCode": "class TimeMap {\n    constructor() {\n        \n    }\n\n    set(key: string, value: string, timestamp: number): void {\n        \n    }\n\n    get(key: string, timestamp: number): string {\n        \n    }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * var obj = new TimeMap()\n * obj.set(key,value,timestamp)\n * var param_2 = obj.get(key,timestamp)\n */"}, {"value": "php", "text": "PHP", "defaultCode": "class TimeMap {\n    /**\n     */\n    function __construct() {\n        \n    }\n  \n    /**\n     * @param String $key\n     * @param String $value\n     * @param Integer $timestamp\n     * @return NULL\n     */\n    function set($key, $value, $timestamp) {\n        \n    }\n  \n    /**\n     * @param String $key\n     * @param Integer $timestamp\n     * @return String\n     */\n    function get($key, $timestamp) {\n        \n    }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * $obj = TimeMap();\n * $obj->set($key, $value, $timestamp);\n * $ret_2 = $obj->get($key, $timestamp);\n */"}, {"value": "swift", "text": "Swift", "defaultCode": "\nclass TimeMap {\n\n    init() {\n        \n    }\n    \n    func set(_ key: String, _ value: String, _ timestamp: Int) {\n        \n    }\n    \n    func get(_ key: String, _ timestamp: Int) -> String {\n        \n    }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * let obj = TimeMap()\n * obj.set(key, value, timestamp)\n * let ret_2: String = obj.get(key, timestamp)\n */"}, {"value": "kotlin", "text": "Kotlin", "defaultCode": "class TimeMap() {\n\n    fun set(key: String, value: String, timestamp: Int) {\n        \n    }\n\n    fun get(key: String, timestamp: Int): String {\n        \n    }\n\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * var obj = TimeMap()\n * obj.set(key,value,timestamp)\n * var param_2 = obj.get(key,timestamp)\n */"}, {"value": "dart", "text": "Dart", "defaultCode": "class TimeMap {\n\n  TimeMap() {\n    \n  }\n  \n  void set(String key, String value, int timestamp) {\n    \n  }\n  \n  String get(String key, int timestamp) {\n    \n  }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * TimeMap obj = TimeMap();\n * obj.set(key,value,timestamp);\n * String param2 = obj.get(key,timestamp);\n */"}, {"value": "golang", "text": "Go", "defaultCode": "type TimeMap struct {\n    \n}\n\n\nfunc Constructor() TimeMap {\n    \n}\n\n\nfunc (this *TimeMap) Set(key string, value string, timestamp int)  {\n    \n}\n\n\nfunc (this *TimeMap) Get(key string, timestamp int) string {\n    \n}\n\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * obj := Constructor();\n * obj.Set(key,value,timestamp);\n * param_2 := obj.Get(key,timestamp);\n */"}, {"value": "ruby", "text": "Ruby", "defaultCode": "class TimeMap\n    def initialize()\n        \n    end\n\n\n=begin\n    :type key: String\n    :type value: String\n    :type timestamp: Integer\n    :rtype: Void\n=end\n    def set(key, value, timestamp)\n        \n    end\n\n\n=begin\n    :type key: String\n    :type timestamp: Integer\n    :rtype: String\n=end\n    def get(key, timestamp)\n        \n    end\n\n\nend\n\n# Your TimeMap object will be instantiated and called as such:\n# obj = TimeMap.new()\n# obj.set(key, value, timestamp)\n# param_2 = obj.get(key, timestamp)"}, {"value": "scala", "text": "Scala", "defaultCode": "class TimeMap() {\n\n    def set(key: String, value: String, timestamp: Int): Unit = {\n        \n    }\n\n    def get(key: String, timestamp: Int): String = {\n        \n    }\n\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * val obj = new TimeMap()\n * obj.set(key,value,timestamp)\n * val param_2 = obj.get(key,timestamp)\n */"}, {"value": "rust", "text": "Rust", "defaultCode": "struct TimeMap {\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 TimeMap {\n\n    fn new() -> Self {\n        \n    }\n    \n    fn set(&self, key: String, value: String, timestamp: i32) {\n        \n    }\n    \n    fn get(&self, key: String, timestamp: i32) -> String {\n        \n    }\n}\n\n/**\n * Your TimeMap object will be instantiated and called as such:\n * let obj = TimeMap::new();\n * obj.set(key, value, timestamp);\n * let ret_2: String = obj.get(key, timestamp);\n */"}, {"value": "racket", "text": "Racket", "defaultCode": "(define time-map%\n  (class object%\n    (super-new)\n    \n    (init-field)\n    \n    ; set : string? string? exact-integer? -> void?\n    (define/public (set key value timestamp)\n      )\n    ; get : string? exact-integer? -> string?\n    (define/public (get key timestamp)\n      )))\n\n;; Your time-map% object will be instantiated and called as such:\n;; (define obj (new time-map%))\n;; (send obj set key value timestamp)\n;; (define param_2 (send obj get key timestamp))"}, {"value": "erlang", "text": "Erlang", "defaultCode": "-spec time_map_init_() -> any().\ntime_map_init_() ->\n  .\n\n-spec time_map_set(Key :: unicode:unicode_binary(), Value :: unicode:unicode_binary(), Timestamp :: integer()) -> any().\ntime_map_set(Key, Value, Timestamp) ->\n  .\n\n-spec time_map_get(Key :: unicode:unicode_binary(), Timestamp :: integer()) -> unicode:unicode_binary().\ntime_map_get(Key, Timestamp) ->\n  .\n\n\n%% Your functions will be called as such:\n%% time_map_init_(),\n%% time_map_set(Key, Value, Timestamp),\n%% Param_2 = time_map_get(Key, Timestamp),\n\n%% time_map_init_ will be called before every test case, in which you can do some necessary initializations."}, {"value": "elixir", "text": "Elixir", "defaultCode": "defmodule TimeMap do\n  @spec init_() :: any\n  def init_() do\n    \n  end\n\n  @spec set(key :: String.t, value :: String.t, timestamp :: integer) :: any\n  def set(key, value, timestamp) do\n    \n  end\n\n  @spec get(key :: String.t, timestamp :: integer) :: String.t\n  def get(key, timestamp) do\n    \n  end\nend\n\n# Your functions will be called as such:\n# TimeMap.init_()\n# TimeMap.set(key, value, timestamp)\n# param_2 = TimeMap.get(key, timestamp)\n\n# TimeMap.init_ will be called before every test case, in which you can do some necessary initializations."}]
{
  "classname": "TimeMap",
  "constructor": {
    "params": []
  },
  "methods": [
    {
      "params": [
        {
          "type": "string",
          "name": "key"
        },
        {
          "type": "string",
          "name": "value"
        },
        {
          "type": "integer",
          "name": "timestamp"
        }
      ],
      "return": {
        "type": "void"
      },
      "name": "set"
    },
    {
      "params": [
        {
          "type": "string",
          "name": "key"
        },
        {
          "type": "integer",
          "name": "timestamp"
        }
      ],
      "return": {
        "type": "string"
      },
      "name": "get"
    }
  ],
  "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>"]}
['Hash Table', 'String', 'Binary Search', 'Design']