{"id":578,"date":"2017-10-14T20:13:20","date_gmt":"2017-10-15T03:13:20","guid":{"rendered":"http:\/\/zxi.mytechroad.com\/blog\/?p=578"},"modified":"2018-04-19T08:37:02","modified_gmt":"2018-04-19T15:37:02","slug":"leetcode-56-merge-intervals","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/geometry\/leetcode-56-merge-intervals\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 56. Merge Intervals"},"content":{"rendered":"<p><iframe loading=\"lazy\" title=\"\u82b1\u82b1\u9171 LeetCode 56. Merge Intervals - \u5237\u9898\u627e\u5de5\u4f5c EP85\" width=\"500\" height=\"375\" src=\"https:\/\/www.youtube.com\/embed\/6tLHjei-f0I?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><strong>Problem:<\/strong><\/p>\n<p>Given a collection of intervals, merge all overlapping intervals.<\/p>\n<p>For example,<br \/>\nGiven\u00a0<code>[1,3],[2,6],[8,10],[15,18]<\/code>,<br \/>\nreturn\u00a0<code>[1,6],[8,10],[15,18]<\/code>.<\/p>\n<p><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script><br \/>\n<ins class=\"adsbygoogle\" style=\"display: block; text-align: center;\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\" data-ad-client=\"ca-pub-2404451723245401\" data-ad-slot=\"7983117522\"><\/ins><br \/>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><\/p>\n<p><strong>Idea:<\/strong><\/p>\n<p>Sweep line<\/p>\n<p><a href=\"http:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2017\/10\/56-ep85-1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-584\" src=\"http:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2017\/10\/56-ep85-1.png\" alt=\"\" width=\"960\" height=\"540\" srcset=\"https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2017\/10\/56-ep85-1.png 960w, https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2017\/10\/56-ep85-1-300x169.png 300w, https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2017\/10\/56-ep85-1-768x432.png 768w, https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2017\/10\/56-ep85-1-624x351.png 624w\" sizes=\"auto, (max-width: 960px) 100vw, 960px\" \/><\/a><\/p>\n<p><strong>Solution: <\/strong><\/p>\n<p>C++<\/p>\n<pre class=\"lang:c++ decode:true\">\/\/ Author: Huahua\r\n\/\/ Runtime: 12 ms\r\nclass Solution {\r\npublic:\r\n    vector&lt;Interval&gt; merge(vector&lt;Interval&gt;&amp; intervals) {\r\n        if (intervals.empty()) return {};\r\n        \r\n        std::sort(intervals.begin(), intervals.end(), \r\n                  [](const Interval&amp; a, const Interval&amp; b){\r\n                        return a.start &lt; b.start;\r\n                    });\r\n        \r\n        vector&lt;Interval&gt; ans;        \r\n        for (const auto&amp; interval : intervals) {\r\n            if (ans.empty() || interval.start &gt; ans.back().end) {\r\n                ans.push_back(interval);\r\n            } else {\r\n                ans.back().end = max(ans.back().end, interval.end);\r\n            }\r\n        }\r\n        \r\n        return ans;\r\n    }\r\n};<\/pre>\n<p>Python<\/p>\n<pre class=\"lang:python decode:true \">\"\"\"\r\nAuthor: Huahua\r\nRuntime: 69 ms\r\n\"\"\"\r\nclass Solution(object):\r\n    def merge(self, intervals):\r\n        ans = []\r\n        for interval in sorted(intervals, key=lambda x: x.start):\r\n            if not ans or interval.start &gt; ans[-1].end:\r\n                ans.append(interval)\r\n            else:\r\n                ans[-1].end = max(ans[-1].end, interval.end)\r\n        return ans\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p><strong>Related Problems:<\/strong><\/p>\n<ul>\n<li><a href=\"http:\/\/zxi.mytechroad.com\/blog\/geometry\/leetcode-57-insert-interval\/\">[\u89e3\u9898\u62a5\u544a] LeetCode 57. Insert Interval<\/a><\/li>\n<li><a href=\"http:\/\/zxi.mytechroad.com\/blog\/tree\/leetcode-218-the-skyline-problem\/\">[\u89e3\u9898\u62a5\u544a] LeetCode 218. The Skyline Problem<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Problem: Given a collection of intervals, merge all overlapping intervals. For example, Given\u00a0[1,3],[2,6],[8,10],[15,18], return\u00a0[1,6],[8,10],[15,18]. Idea: Sweep line Solution: C++ \/\/ Author: Huahua \/\/ Runtime: 12&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[127],"tags":[128,129,23,104],"class_list":["post-578","post","type-post","status-publish","format-standard","hentry","category-geometry","tag-interval","tag-merge","tag-sort","tag-sweep-line","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/578","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=578"}],"version-history":[{"count":6,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/578\/revisions"}],"predecessor-version":[{"id":2645,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/578\/revisions\/2645"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=578"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=578"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=578"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}