{"id":6665,"date":"2020-04-26T00:37:05","date_gmt":"2020-04-26T07:37:05","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=6665"},"modified":"2020-04-27T19:53:35","modified_gmt":"2020-04-28T02:53:35","slug":"leetcode-1424-diagonal-traverse-ii","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/hashtable\/leetcode-1424-diagonal-traverse-ii\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 1424. Diagonal Traverse II"},"content":{"rendered":"\n<figure class=\"wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-4-3 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"\u82b1\u82b1\u9171 LeetCode 1424. Diagonal Traverse II - \u5237\u9898\u627e\u5de5\u4f5c EP322\" width=\"500\" height=\"375\" src=\"https:\/\/www.youtube.com\/embed\/9J3IRkjkIkQ?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>\n<\/div><\/figure>\n\n\n\n<p>Given a list of lists of integers,&nbsp;<code>nums<\/code>,&nbsp;return all elements of&nbsp;<code>nums<\/code>&nbsp;in diagonal order as shown in the below images.<\/p>\n\n\n\n<p><strong>Example 1:<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/assets.leetcode.com\/uploads\/2020\/04\/08\/sample_1_1784.png\" alt=\"\"\/><\/figure>\n\n\n\n<pre class=\"wp-block-preformatted;crayon:false\"><strong>Input:<\/strong> nums = [[1,2,3],[4,5,6],[7,8,9]]\n<strong>Output:<\/strong> [1,4,2,7,5,3,8,6,9]\n<\/pre>\n\n\n\n<p><strong>Example 2:<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/assets.leetcode.com\/uploads\/2020\/04\/08\/sample_2_1784.png\" alt=\"\"\/><\/figure>\n\n\n\n<pre class=\"wp-block-preformatted;crayon:false\"><strong>Input:<\/strong> nums = [[1,2,3,4,5],[6,7],[8],[9,10,11],[12,13,14,15,16]]\n<strong>Output:<\/strong> [1,6,2,8,7,3,9,4,12,10,5,13,11,14,15,16]\n<\/pre>\n\n\n\n<p><strong>Example 3:<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted;crayon:false\"><strong>Input:<\/strong> nums = [[1,2,3],[4],[5,6,7],[8],[9,10,11]]\n<strong>Output:<\/strong> [1,4,2,5,3,8,6,9,7,10,11]\n<\/pre>\n\n\n\n<p><strong>Example 4:<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted;crayon:false\"><strong>Input:<\/strong> nums = [[1,2,3,4,5,6]]\n<strong>Output:<\/strong> [1,2,3,4,5,6]\n<\/pre>\n\n\n\n<p><strong>Constraints:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><code>1 &lt;= nums.length &lt;= 10^5<\/code><\/li><li><code>1 &lt;= nums[i].length &lt;=&nbsp;10^5<\/code><\/li><li><code>1 &lt;= nums[i][j] &lt;= 10^9<\/code><\/li><li>There at most&nbsp;<code>10^5<\/code>&nbsp;elements in&nbsp;<code>nums<\/code>.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Solution: Hashtable<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"960\" height=\"540\" src=\"https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2020\/04\/1424-ep322.png\" alt=\"\" class=\"wp-image-6676\" srcset=\"https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2020\/04\/1424-ep322.png 960w, https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2020\/04\/1424-ep322-300x169.png 300w, https:\/\/zxi.mytechroad.com\/blog\/wp-content\/uploads\/2020\/04\/1424-ep322-768x432.png 768w\" sizes=\"auto, (max-width: 960px) 100vw, 960px\" \/><\/figure>\n\n\n\n<p>Use diagonal index (i + j) as key.<\/p>\n\n\n\n<p>Time complexity: O(n)<br>Space complexity: O(n)<\/p>\n\n\n\n<div class=\"responsive-tabs\">\n<h2 class=\"tabtitle\">C++<\/h2>\n<div class=\"tabcontent\">\n\n<pre lang=\"C++\">\n\/\/ Author: Huahua\nclass Solution {\npublic:\n  vector<int> findDiagonalOrder(vector<vector<int>>& nums) {\n    vector<vector<int>> m;    \n    for (int i = 0; i < nums.size(); ++i)\n      for (int j = 0; j < nums[i].size(); ++j) {\n        if (m.size() <= i + j) m.push_back({});\n        m[i + j].push_back(nums[i][j]);\n    }\n    vector<int> ans;    \n    for (const auto& d : m)\n      ans.insert(end(ans), rbegin(d), rend(d));\n    return ans;\n  }\n};\n<\/pre>\n<\/div><\/div>\n\n\n\n<div class=\"responsive-tabs\">\n<h2 class=\"tabtitle\">Python<\/h2>\n<div class=\"tabcontent\">\n\n<pre lang=\"Python\">\n# Author: Huahua\nclass Solution:\n  def findDiagonalOrder(self, nums):\n    m = []\n    for i, row in enumerate(nums):\n      for j, v in enumerate(row):\n        if i + j >= len(m): m.append([])\n        m[i+j].append(v)\n    return [v for d in m for v in reversed(d)]\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Given a list of lists of integers,&nbsp;nums,&nbsp;return all elements of&nbsp;nums&nbsp;in diagonal order as shown in the below images. Example 1: Input: nums = [[1,2,3],[4,5,6],[7,8,9]] Output:&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[70],"tags":[535,82,177],"class_list":["post-6665","post","type-post","status-publish","format-standard","hentry","category-hashtable","tag-diagonal","tag-hashtable","tag-medium","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/6665","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=6665"}],"version-history":[{"count":4,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/6665\/revisions"}],"predecessor-version":[{"id":6678,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/6665\/revisions\/6678"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=6665"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=6665"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=6665"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}