Kth Largest Element in a Stream
<p>You are part of a university admissions office and need to keep track of the <code>kth</code> highest test score from applicants in real-time. This helps to determine cut-off marks for interviews and admissions dynamically as new applicants submit their scores.</p>

<p>You are tasked to implement a class which, for a given integer&nbsp;<code>k</code>, maintains a stream of test scores and continuously returns the&nbsp;<code>k</code>th highest test score&nbsp;<strong>after</strong>&nbsp;a new score has been submitted. More specifically, we are looking for the <code>k</code>th highest score in the sorted list of all scores.</p>

<p>Implement the&nbsp;<code>KthLargest</code> class:</p>

<ul>
	<li><code>KthLargest(int k, int[] nums)</code> Initializes the object with the integer <code>k</code> and the stream of test scores&nbsp;<code>nums</code>.</li>
	<li><code>int add(int val)</code> Adds a new test score&nbsp;<code>val</code> to the stream and returns the element representing the <code>k<sup>th</sup></code> largest element in the pool of test scores so far.</li>
</ul>

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

<div class="example-block">
<p><strong>Input:</strong><br />
<span class="example-io">[&quot;KthLargest&quot;, &quot;add&quot;, &quot;add&quot;, &quot;add&quot;, &quot;add&quot;, &quot;add&quot;]<br />
[[3, [4, 5, 8, 2]], [3], [5], [10], [9], [4]]</span></p>

<p><strong>Output:</strong> <span class="example-io">[null, 4, 5, 5, 8, 8]</span></p>

<p><strong>Explanation:</strong></p>

<p>KthLargest kthLargest = new KthLargest(3, [4, 5, 8, 2]);<br />
kthLargest.add(3); // return 4<br />
kthLargest.add(5); // return 5<br />
kthLargest.add(10); // return 5<br />
kthLargest.add(9); // return 8<br />
kthLargest.add(4); // return 8</p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong><br />
<span class="example-io">[&quot;KthLargest&quot;, &quot;add&quot;, &quot;add&quot;, &quot;add&quot;, &quot;add&quot;]<br />
[[4, [7, 7, 7, 7, 8, 3]], [2], [10], [9], [9]]</span></p>

<p><strong>Output:</strong> <span class="example-io">[null, 7, 7, 7, 8]</span></p>

<p><strong>Explanation:</strong></p>
KthLargest kthLargest = new KthLargest(4, [7, 7, 7, 7, 8, 3]);<br />
kthLargest.add(2); // return 7<br />
kthLargest.add(10); // return 7<br />
kthLargest.add(9); // return 7<br />
kthLargest.add(9); // return 8</div>

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

<ul>
	<li><code>0 &lt;= nums.length &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= k &lt;= nums.length + 1</code></li>
	<li><code>-10<sup>4</sup> &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
	<li><code>-10<sup>4</sup> &lt;= val &lt;= 10<sup>4</sup></code></li>
	<li>At most <code>10<sup>4</sup></code> calls will be made to <code>add</code>.</li>
</ul>

['kth-largest-element-in-an-array', 'finding-mk-average', 'sequentially-ordinal-rank-tracker']
[]
[{"value": "cpp", "text": "C++", "defaultCode": "class KthLargest {\npublic:\n    KthLargest(int k, vector<int>& nums) {\n        \n    }\n    \n    int add(int val) {\n        \n    }\n};\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * KthLargest* obj = new KthLargest(k, nums);\n * int param_1 = obj->add(val);\n */"}, {"value": "java", "text": "Java", "defaultCode": "class KthLargest {\n\n    public KthLargest(int k, int[] nums) {\n        \n    }\n    \n    public int add(int val) {\n        \n    }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * KthLargest obj = new KthLargest(k, nums);\n * int param_1 = obj.add(val);\n */"}, {"value": "python", "text": "Python", "defaultCode": "class KthLargest(object):\n\n    def __init__(self, k, nums):\n        \"\"\"\n        :type k: int\n        :type nums: List[int]\n        \"\"\"\n        \n\n    def add(self, val):\n        \"\"\"\n        :type val: int\n        :rtype: int\n        \"\"\"\n        \n\n\n# Your KthLargest object will be instantiated and called as such:\n# obj = KthLargest(k, nums)\n# param_1 = obj.add(val)"}, {"value": "python3", "text": "Python3", "defaultCode": "class KthLargest:\n\n    def __init__(self, k: int, nums: List[int]):\n        \n\n    def add(self, val: int) -> int:\n        \n\n\n# Your KthLargest object will be instantiated and called as such:\n# obj = KthLargest(k, nums)\n# param_1 = obj.add(val)"}, {"value": "c", "text": "C", "defaultCode": "\n\n\ntypedef struct {\n    \n} KthLargest;\n\n\nKthLargest* kthLargestCreate(int k, int* nums, int numsSize) {\n    \n}\n\nint kthLargestAdd(KthLargest* obj, int val) {\n    \n}\n\nvoid kthLargestFree(KthLargest* obj) {\n    \n}\n\n/**\n * Your KthLargest struct will be instantiated and called as such:\n * KthLargest* obj = kthLargestCreate(k, nums, numsSize);\n * int param_1 = kthLargestAdd(obj, val);\n \n * kthLargestFree(obj);\n*/"}, {"value": "csharp", "text": "C#", "defaultCode": "public class KthLargest {\n\n    public KthLargest(int k, int[] nums) {\n        \n    }\n    \n    public int Add(int val) {\n        \n    }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * KthLargest obj = new KthLargest(k, nums);\n * int param_1 = obj.Add(val);\n */"}, {"value": "javascript", "text": "JavaScript", "defaultCode": "/**\n * @param {number} k\n * @param {number[]} nums\n */\nvar KthLargest = function(k, nums) {\n    \n};\n\n/** \n * @param {number} val\n * @return {number}\n */\nKthLargest.prototype.add = function(val) {\n    \n};\n\n/** \n * Your KthLargest object will be instantiated and called as such:\n * var obj = new KthLargest(k, nums)\n * var param_1 = obj.add(val)\n */"}, {"value": "typescript", "text": "TypeScript", "defaultCode": "class KthLargest {\n    constructor(k: number, nums: number[]) {\n        \n    }\n\n    add(val: number): number {\n        \n    }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * var obj = new KthLargest(k, nums)\n * var param_1 = obj.add(val)\n */"}, {"value": "php", "text": "PHP", "defaultCode": "class KthLargest {\n    /**\n     * @param Integer $k\n     * @param Integer[] $nums\n     */\n    function __construct($k, $nums) {\n        \n    }\n  \n    /**\n     * @param Integer $val\n     * @return Integer\n     */\n    function add($val) {\n        \n    }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * $obj = KthLargest($k, $nums);\n * $ret_1 = $obj->add($val);\n */"}, {"value": "swift", "text": "Swift", "defaultCode": "\nclass KthLargest {\n\n    init(_ k: Int, _ nums: [Int]) {\n        \n    }\n    \n    func add(_ val: Int) -> Int {\n        \n    }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * let obj = KthLargest(k, nums)\n * let ret_1: Int = obj.add(val)\n */"}, {"value": "kotlin", "text": "Kotlin", "defaultCode": "class KthLargest(k: Int, nums: IntArray) {\n\n    fun add(`val`: Int): Int {\n        \n    }\n\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * var obj = KthLargest(k, nums)\n * var param_1 = obj.add(`val`)\n */"}, {"value": "dart", "text": "Dart", "defaultCode": "class KthLargest {\n\n  KthLargest(int k, List<int> nums) {\n    \n  }\n  \n  int add(int val) {\n    \n  }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * KthLargest obj = KthLargest(k, nums);\n * int param1 = obj.add(val);\n */"}, {"value": "golang", "text": "Go", "defaultCode": "type KthLargest struct {\n    \n}\n\n\nfunc Constructor(k int, nums []int) KthLargest {\n    \n}\n\n\nfunc (this *KthLargest) Add(val int) int {\n    \n}\n\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * obj := Constructor(k, nums);\n * param_1 := obj.Add(val);\n */"}, {"value": "ruby", "text": "Ruby", "defaultCode": "class KthLargest\n\n=begin\n    :type k: Integer\n    :type nums: Integer[]\n=end\n    def initialize(k, nums)\n        \n    end\n\n\n=begin\n    :type val: Integer\n    :rtype: Integer\n=end\n    def add(val)\n        \n    end\n\n\nend\n\n# Your KthLargest object will be instantiated and called as such:\n# obj = KthLargest.new(k, nums)\n# param_1 = obj.add(val)"}, {"value": "scala", "text": "Scala", "defaultCode": "class KthLargest(_k: Int, _nums: Array[Int]) {\n\n    def add(`val`: Int): Int = {\n        \n    }\n\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * val obj = new KthLargest(k, nums)\n * val param_1 = obj.add(`val`)\n */"}, {"value": "rust", "text": "Rust", "defaultCode": "struct KthLargest {\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 KthLargest {\n\n    fn new(k: i32, nums: Vec<i32>) -> Self {\n        \n    }\n    \n    fn add(&self, val: i32) -> i32 {\n        \n    }\n}\n\n/**\n * Your KthLargest object will be instantiated and called as such:\n * let obj = KthLargest::new(k, nums);\n * let ret_1: i32 = obj.add(val);\n */"}, {"value": "racket", "text": "Racket", "defaultCode": "(define kth-largest%\n  (class object%\n    (super-new)\n    \n    ; k : exact-integer?\n    ; nums : (listof exact-integer?)\n    (init-field\n      k\n      nums)\n    \n    ; add : exact-integer? -> exact-integer?\n    (define/public (add val)\n      )))\n\n;; Your kth-largest% object will be instantiated and called as such:\n;; (define obj (new kth-largest% [k k] [nums nums]))\n;; (define param_1 (send obj add val))"}, {"value": "erlang", "text": "Erlang", "defaultCode": "-spec kth_largest_init_(K :: integer(), Nums :: [integer()]) -> any().\nkth_largest_init_(K, Nums) ->\n  .\n\n-spec kth_largest_add(Val :: integer()) -> integer().\nkth_largest_add(Val) ->\n  .\n\n\n%% Your functions will be called as such:\n%% kth_largest_init_(K, Nums),\n%% Param_1 = kth_largest_add(Val),\n\n%% kth_largest_init_ will be called before every test case, in which you can do some necessary initializations."}, {"value": "elixir", "text": "Elixir", "defaultCode": "defmodule KthLargest do\n  @spec init_(k :: integer, nums :: [integer]) :: any\n  def init_(k, nums) do\n    \n  end\n\n  @spec add(val :: integer) :: integer\n  def add(val) do\n    \n  end\nend\n\n# Your functions will be called as such:\n# KthLargest.init_(k, nums)\n# param_1 = KthLargest.add(val)\n\n# KthLargest.init_ will be called before every test case, in which you can do some necessary initializations."}]
{
  "classname": "KthLargest",
  "constructor": {
    "params": [
      {
        "type": "integer",
        "name": "k"
      },
      {
        "type": "integer[]",
        "name": "nums"
      },
      {
        "type": "integer",
        "name": "numsSize",
        "lang": "c",
        "value": "size_2"
      }
    ]
  },
  "methods": [
    {
      "name": "add",
      "params": [
        {
          "type": "integer",
          "name": "val"
        }
      ],
      "return": {
        "type": "integer"
      }
    }
  ],
  "systemdesign": true,
  "params": [
    {
      "name": "starts",
      "type": "integer[]"
    },
    {
      "name": "ends",
      "type": "integer[]"
    }
  ],
  "return": {
    "type": "list<boolean>",
    "dealloc": true
  },
  "manual": false
}
{"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>"]}
['Tree', 'Design', 'Binary Search Tree', 'Heap (Priority Queue)', 'Binary Tree', 'Data Stream']