{"id":3095,"date":"2018-07-12T20:33:59","date_gmt":"2018-07-13T03:33:59","guid":{"rendered":"http:\/\/zxi.mytechroad.com\/blog\/?p=3095"},"modified":"2018-07-12T20:40:25","modified_gmt":"2018-07-13T03:40:25","slug":"leetcode-703-kth-largest-element-in-a-stream","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/heap\/leetcode-703-kth-largest-element-in-a-stream\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 703. Kth Largest Element in a Stream"},"content":{"rendered":"<h1><strong>Problem<\/strong><\/h1>\n<p>Design a class to find\u00a0the\u00a0<strong>k<\/strong>th largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element.<\/p>\n<p>Your\u00a0<code>KthLargest<\/code>\u00a0class will have a constructor which accepts an integer\u00a0<code>k<\/code>\u00a0and an integer array\u00a0<code>nums<\/code>, which contains initial elements from\u00a0the stream. For each call to the method\u00a0<code>KthLargest.add<\/code>, return the element representing the kth largest element in the stream.<\/p>\n<p><strong>Example:<\/strong><\/p>\n<pre class=\"crayon:false\">int k = 3;\r\nint[] arr = [4,5,8,2];\r\nKthLargest kthLargest = new KthLargest(3, arr);\r\nkthLargest.add(3);\u00a0 \u00a0\/\/ returns 4\r\nkthLargest.add(5);\u00a0 \u00a0\/\/ returns 5\r\nkthLargest.add(10);\u00a0 \/\/ returns 5\r\nkthLargest.add(9);\u00a0 \u00a0\/\/ returns 8\r\nkthLargest.add(4);\u00a0 \u00a0\/\/ returns 8\r\n<\/pre>\n<p><strong>Note:\u00a0<\/strong><br \/>\nYou may assume that\u00a0<code>nums<\/code>&#8216; length\u00a0\u2265\u00a0<code>k-1<\/code>\u00a0and\u00a0<code>k<\/code>\u00a0\u2265\u00a01.<\/p>\n<h1><strong>Solution: BST \/ Min Heap<\/strong><\/h1>\n<p>Time complexity: O(nlogk)<\/p>\n<p>Space complexity: O(k)<\/p>\n<p>C++ \/ BST<\/p>\n<pre class=\"lang:default decode:true\">\/\/ Author: Huahua\r\n\/\/ Running time: 32 ms\r\nclass KthLargest {\r\npublic:\r\n  KthLargest(int k, vector&lt;int&gt; nums): k_(k) {\r\n    for (int num : nums)\r\n      add(num);\r\n  }\r\n\r\n  int add(int val) {    \r\n    s_.insert(val);\r\n    if (s_.size() &gt; k_)\r\n      s_.erase(s_.begin());\r\n    return *s_.begin();\r\n  }\r\nprivate:\r\n  const int k_;  \r\n  multiset&lt;int&gt; s_;\r\n};<\/pre>\n<p>C++ \/ Min Heap<\/p>\n<pre class=\"lang:default decode:true  \">\/\/ Author: Huahua\r\n\/\/ Running time: 28 ms\r\nclass KthLargest {\r\npublic:\r\n  KthLargest(int k, vector&lt;int&gt; nums): k_(k) {    \r\n    for (int num : nums)\r\n      add(num);\r\n  }\r\n\r\n  int add(int val) {    \r\n    s_.push(val);\r\n    if (s_.size() &gt; k_)\r\n      s_.pop();\r\n    return s_.top();\r\n  }\r\nprivate:\r\n  const int k_;  \r\n  priority_queue&lt;int, vector&lt;int&gt;, greater&lt;int&gt;&gt; s_; \/\/ min heap\r\n};<\/pre>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Problem Design a class to find\u00a0the\u00a0kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[71],"tags":[74,222,73,90,323],"class_list":["post-3095","post","type-post","status-publish","format-standard","hentry","category-heap","tag-bst","tag-easy","tag-heap","tag-stream","tag-top-k","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/3095","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/comments?post=3095"}],"version-history":[{"count":3,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/3095\/revisions"}],"predecessor-version":[{"id":3098,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/3095\/revisions\/3098"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=3095"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=3095"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=3095"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}