{"id":2386,"date":"2022-04-10T15:01:20","date_gmt":"2022-04-10T07:01:20","guid":{"rendered":"https:\/\/jimmyswebnote.com\/?p=2386"},"modified":"2022-04-10T15:16:09","modified_gmt":"2022-04-10T07:16:09","slug":"tree","status":"publish","type":"post","link":"https:\/\/jimmyswebnote.com\/tree\/","title":{"rendered":"\u8cc7\u6599\u7d50\u69cb\u7b46\u8a18 3 &#8211; Tree"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6633508b0200e\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6633508b0200e\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/jimmyswebnote.com\/tree\/#1_%E5%AE%9A%E7%BE%A9%E8%88%87%E7%89%B9%E6%80%A7\" title=\"1. \u5b9a\u7fa9\u8207\u7279\u6027\">1. \u5b9a\u7fa9\u8207\u7279\u6027<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/jimmyswebnote.com\/tree\/#11_%E5%AE%9A%E7%BE%A9\" title=\"1.1 \u5b9a\u7fa9\">1.1 \u5b9a\u7fa9<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/jimmyswebnote.com\/tree\/#12_%E7%89%B9%E6%80%A7\" title=\"1.2 \u7279\u6027\">1.2 \u7279\u6027<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/jimmyswebnote.com\/tree\/#2_JavaScript_%E5%AF%A6%E4%BD%9C\" title=\"2. JavaScript \u5be6\u4f5c\">2. JavaScript \u5be6\u4f5c<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/jimmyswebnote.com\/tree\/#21_Node\" title=\"2.1 Node\">2.1 Node<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/jimmyswebnote.com\/tree\/#22_Tree\" title=\"2.2 Tree\">2.2 Tree<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/jimmyswebnote.com\/tree\/#221_%E5%BB%BA%E7%AB%8B_tree\" title=\"2.2.1 \u5efa\u7acb tree\">2.2.1 \u5efa\u7acb tree<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/jimmyswebnote.com\/tree\/#222_BFS_%E2%80%93_Breadth-first_Search_%E5%BB%A3%E5%BA%A6%E5%84%AA%E5%85%88%E6%90%9C%E5%B0%8B\" title=\"2.2.2 BFS &#8211; Breadth-first Search (\u5ee3\u5ea6\u512a\u5148\u641c\u5c0b)\">2.2.2 BFS &#8211; Breadth-first Search (\u5ee3\u5ea6\u512a\u5148\u641c\u5c0b)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/jimmyswebnote.com\/tree\/#223_DFS_%E2%80%93_Depth-first_Search_%E6%B7%B1%E5%BA%A6%E5%84%AA%E5%85%88%E6%90%9C%E5%B0%8B\" title=\"2.2.3 DFS &#8211; Depth-first Search (\u6df1\u5ea6\u512a\u5148\u641c\u5c0b)\">2.2.3 DFS &#8211; Depth-first Search (\u6df1\u5ea6\u512a\u5148\u641c\u5c0b)<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/jimmyswebnote.com\/tree\/#3_%E5%8F%83%E8%80%83%E8%B3%87%E6%96%99\" title=\"3. \u53c3\u8003\u8cc7\u6599\">3. \u53c3\u8003\u8cc7\u6599<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"1_%E5%AE%9A%E7%BE%A9%E8%88%87%E7%89%B9%E6%80%A7\"><\/span>1. \u5b9a\u7fa9\u8207\u7279\u6027<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3><span class=\"ez-toc-section\" id=\"11_%E5%AE%9A%E7%BE%A9\"><\/span>1.1 \u5b9a\u7fa9<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Tree \u662f\u6700\u5e38\u898b\u7684 non-linear data structure\uff0c\u69cb\u6210 tree \u7684\u57fa\u672c\u55ae\u4f4d\u70ba node\uff0c\u4ee5\u4e0b\u70ba tree \u7684\u5b9a\u7fa9\uff1a<\/p>\n\n\n\n<ul><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Root Node<\/span><\/strong>\uff1a(\u6839\u7bc0\u9ede)\u70ba tree \u7684\u8d77\u9ede\uff0c\u6bcf\u4e00\u500b tree \u50c5\u6709\u4e00\u500b\u4e14\u552f\u4e00\u7684 root node<ul><li>A \u70ba root node<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">SubTree<\/span><\/strong>\uff1a\u6bcf\u500b node \u5e95\u4e0b\u53ef\u4ee5\u5206\u70ba\u4e92\u4e0d\u76f8\u4ea4\u7684\u6709\u9650\u96c6\u5408\uff0c\u7a31\u70ba subTree\uff0c\u4ee5\u4e0b\u7528 T \u4f86\u8868\u793a<ul><li>A \u6709\u5169\u500b subTree: T1(B, D, G, H, I)\u3001T2(C, E, F)<\/li><li>B \u6709\u4e00\u500b subTree: T1(D, G, H, I)<\/li><li>C \u6709\u5169\u500b subTree: T1(E)\u3001T2(F)<\/li><li>D \u6709\u4e09\u500b subTree: T1(G)\u3001T2(H)\u3001T3(I)<\/li><\/ul><\/li><\/ul>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\"><img loading=\"lazy\" src=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\" alt=\"\" class=\"wp-image-2387\" width=\"336\" height=\"251\" srcset=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png 671w, https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1-300x224.png 300w\" sizes=\"(max-width: 336px) 100vw, 336px\" \/><\/a><\/figure><\/div>\n\n\n\n<h3><span class=\"ez-toc-section\" id=\"12_%E7%89%B9%E6%80%A7\"><\/span>1.2 \u7279\u6027<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>n \u70ba tree \u4e2d\u7684 node \u6578\uff0c\u4efb\u4e00 n &gt; 0 \u7684 tree \u6709\u4ee5\u4e0b\u7684\u7279\u6027\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\"><img loading=\"lazy\" src=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\" alt=\"tree\" class=\"wp-image-2387\" width=\"336\" height=\"251\" srcset=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png 671w, https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1-300x224.png 300w\" sizes=\"(max-width: 336px) 100vw, 336px\" \/><\/a><\/figure><\/div>\n\n\n\n<ul><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Degree<\/span><\/strong>\uff1a\u6bcf\u500b node \u64c1\u6709\u7684 subTree \u500b\u6578\u7a31\u70ba degree<ul><li>A \u7684 degree = 2<\/li><li>B \u7684 degree = 1<\/li><li>C \u7684 degree = 2<\/li><li>D \u7684 degree = 3<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Leaf Node \/ External Node<\/span><\/strong>\uff1adegree = 0 \u7684 node \u7a31\u70ba leaf node (\u8449\u7bc0\u9ede) \u6216 external node (\u5916\u90e8\u7bc0\u9ede)<ul><li>E, F, G, H, I \u70ba leaf node \u4ea6\u70ba external node<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Internal Node<\/span><\/strong>\uff1adegree &gt;= 1 \u7684 node \u7a31\u70ba internal node (\u5167\u90e8\u7bc0\u9ede)<ul><li>B, C, D \u70ba internal node<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Child Node<\/span><\/strong>\uff1anode \u7684 subTree \u7684 root node \u7a31\u70ba\u8a72 node \u7684 child node<ul><li>B, C \u70ba A \u7684 child node<\/li><li>D \u70ba B \u7684 child node<\/li><li>G, H, I \u70ba D \u7684 child node<\/li><li>E, F \u70ba C \u7684 child node<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Parent Node<\/span><\/strong>\uff1anode \u7684 subTree \u7684 root node \u7a31\u8a72 node \u70ba parent node<ul><li>A \u70ba B, C \u7684 parent node<\/li><li>B \u70ba D \u7684 parent node<\/li><li>D \u70ba G, H, I \u7684 parent node<\/li><li>C \u70ba E, F \u7684 parent node<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Siblings<\/span><\/strong>\uff1aparent node \u4e00\u6a23\u7684 node \u7a31\u70ba siblings<ul><li>B, C \u70ba\u5f7c\u6b64\u7684 siblings<\/li><li>G, H, I \u70ba\u5f7c\u6b64\u7684 siblings<\/li><li>E, F \u70ba\u5f7c\u6b64\u7684 siblings<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Ancestor Node<\/span><\/strong>\uff1a\u67d0\u500b node \u5230 root node \u8def\u5f91\u4e0a\u7684\u4efb\u610f node \u7686\u70ba\u8a72 node \u7684 ancestor node<ul><li>A, B, D \u70ba G \u7684 ancestor node<\/li><li>A, C \u70ba E \u7684 ancestor node<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Descendant Node<\/span><\/strong>\uff1a\u67d0\u500b node \u7684 subTree \u4e0a\u7684\u6240\u6709\u7bc0\u9ede\u7686\u70ba\u8a72 node \u7684 descendant node<ul><li>A \u7684 descendant node \u70ba\u6b64 tree \u4e2d\u7684\u6240\u6709 node (\u9664\u4e86 A)<\/li><li>B \u7684 descendant node \u70ba D, G, H, I<\/li><li>C \u7684 descendant node \u70ba E, F<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Level<\/span><\/strong>\uff1anode \u7684 level \u5f9e root node \u5b9a\u7fa9\u8d77\uff0croot node \u7684 level \u70ba 1\uff0c\u5176 child \u7684 level \u70ba 2\uff0c\u4ee5\u6b64\u985e\u63a8<ul><li>A \u7684 level = 1<\/li><li>B, C \u7684 level = 2<\/li><li>D, E, F \u7684 level = 3<\/li><li>G, H, I \u7684 level = 4<\/li><\/ul><\/li><li><strong><span style=\"color:#0071a1\" class=\"has-inline-color\">Depth<\/span><\/strong>\uff1adepth \u70ba\u67d0\u500b node \u5230 root node \u7684 level \u5dee<ul><li>B, C \u7684 depth = 1<\/li><li>D, E, F \u7684 depth = 2<\/li><li>G, H, I \u7684 depth = 3<\/li><li>\u6b64 tree \u7684 depth = 4<\/li><\/ul><\/li><\/ul>\n\n\n\n<h2><span class=\"ez-toc-section\" id=\"2_JavaScript_%E5%AF%A6%E4%BD%9C\"><\/span>2. JavaScript \u5be6\u4f5c<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3><span class=\"ez-toc-section\" id=\"21_Node\"><\/span>2.1 Node<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">class Node {\n  constructor(data) {\n    this.data = data;\n    this.children = [];\n  }\n  add(data) {\n    this.children.push(new Node(data));\n  }\n  remove(data) {\n    this.children = this.children.filter(node =&gt; node.data !== data);\n  }\n}<\/code><\/pre>\n\n\n\n<h3><span class=\"ez-toc-section\" id=\"22_Tree\"><\/span>2.2 Tree<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h4><span class=\"ez-toc-section\" id=\"221_%E5%BB%BA%E7%AB%8B_tree\"><\/span>2.2.1 \u5efa\u7acb tree<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u4ee5\u6b64\u5716\u70ba\u4f8b\uff0c\u5efa\u7acb\u8a72 tree\uff1a<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\"><img loading=\"lazy\" src=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\" alt=\"tree\" class=\"wp-image-2387\" width=\"336\" height=\"251\" srcset=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png 671w, https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1-300x224.png 300w\" sizes=\"(max-width: 336px) 100vw, 336px\" \/><\/a><\/figure><\/div>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">class Tree {\n  constructor() {\n    this.root = null;\n  }\n}\n\nconst t = new Tree();\nt.root = new Node('A');\nt.root.add('B');\nt.root.add('C');\nt.root.children[0].add('D');\nt.root.children[0].children[0].add('G');\nt.root.children[0].children[0].add('H');\nt.root.children[0].children[0].add('I');\nt.root.children[1].add('E');\nt.root.children[1].add('F');<\/code><\/pre>\n\n\n\n<p>\u901a\u5e38 tree \u88e1\u9762\u6703\u6709\u5169\u500b method \u7528\u4f86\u5b58\u53d6 (\u904d\u6b77) tree \u4e2d\u7684\u6bcf\u500b\u7bc0\u9ede\uff0c\u7a31\u70ba traversal (\u8d70\u8a2a)\u3002<\/p>\n\n\n\n<h4><span class=\"ez-toc-section\" id=\"222_BFS_%E2%80%93_Breadth-first_Search_%E5%BB%A3%E5%BA%A6%E5%84%AA%E5%85%88%E6%90%9C%E5%B0%8B\"><\/span>2.2.2 BFS &#8211; Breadth-first Search (\u5ee3\u5ea6\u512a\u5148\u641c\u5c0b)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u5ee3\u5ea6\u512a\u5148\uff0c\u5c31\u662f\u6703\u5148\u8a2a\u554f\u4e00\u6a23\u6df1\u5ea6\u7684 (\u4e5f\u5c31\u662f\u4e00\u6a23\u5ee3\u5ea6\u7684 node ) \u5f8c\uff0c\u518d\u5f80\u66f4\u6df1\u7684\u6df1\u5ea6\u8a2a\u554f\u3002\u4ee5\u4e0b\u5716\u70ba\u4f8b\uff0c\u904d\u6b77\u7684\u9806\u5e8f\u70ba\uff1aA, B, C, D, E, F, G, H, I\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\"><img loading=\"lazy\" src=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\" alt=\"tree\" class=\"wp-image-2387\" width=\"336\" height=\"251\" srcset=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png 671w, https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1-300x224.png 300w\" sizes=\"(max-width: 336px) 100vw, 336px\" \/><\/a><\/figure><\/div>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">traverseBF(fn) {\n  const arr = [this.root];\n  while (arr.length) {\n    const node = arr.shift();\n    arr.push(...node.children);\n    fn(node);\n  }\n}<\/code><\/pre>\n\n\n\n<h4><span class=\"ez-toc-section\" id=\"223_DFS_%E2%80%93_Depth-first_Search_%E6%B7%B1%E5%BA%A6%E5%84%AA%E5%85%88%E6%90%9C%E5%B0%8B\"><\/span>2.2.3 DFS &#8211; Depth-first Search (\u6df1\u5ea6\u512a\u5148\u641c\u5c0b)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u6df1\u5ea6\u512a\u5148\u6703\u7531\u5de6\u81f3\u53f3\u8a2a\u554f\u6700\u6df1\u7684 node \u5f8c\uff0c\u518d\u5f80\u53f3\u5074\u7684 node \u8a2a\u554f\uff0c\u4ee5\u4e0b\u5716\u7684 tree \u70ba\u4f8b\uff0c\u8a2a\u554f\u7684\u9806\u5e8f\u70ba\uff1aA, B, D, G, H, I, C, E, F\u3002<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-large is-resized\"><img loading=\"lazy\" src=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png\" alt=\"tree\" class=\"wp-image-2387\" width=\"336\" height=\"251\" srcset=\"https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1.png 671w, https:\/\/jimmyswebnote.com\/wp-content\/uploads\/2022\/04\/tree1-300x224.png 300w\" sizes=\"(max-width: 336px) 100vw, 336px\" \/><\/figure><\/div>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">traverseDF(fn) {\n  const arr = [this.root];\n  while (arr.length) {\n    const node = arr.shift();\n    arr.unshift(...node.children);\n    fn(node);\n  }\n}<\/code><\/pre>\n\n\n\n<p>\u5b8c\u6574\u7684 code\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">class Tree {\n  constructor() {\n    this.root = null;\n  }\n\n  traverseBF(fn) {\n    const arr = [this.root];\n    while (arr.length) {\n      const node = arr.shift();\n      arr.push(...node.children);\n      fn(node);\n    }\n  }\n\n  traverseDF(fn) {\n    const arr = [this.root];\n    while (arr.length) {\n      const node = arr.shift();\n      arr.unshift(...node.children);\n      fn(node);\n    }\n  }\n}\n\n\/\/ Building a tree\nconst t = new Tree();\nt.root = new Node('A');\nt.root.add('B');\nt.root.add('C');\nt.root.children[0].add('D');\nt.root.children[0].children[0].add('G');\nt.root.children[0].children[0].add('H');\nt.root.children[0].children[0].add('I');\nt.root.children[1].add('E');\nt.root.children[1].add('F');\n\n\/\/ Traverse the tree\nconst lettersBF = [];\nconst lettersDF = [];\nt.traverseBF(node =&gt; {\n  lettersBF.push(node.data);\n});\n\nt.traverseDF(node =&gt; {\n  lettersDF.push(node.data);\n})\n\nconsole.log(lettersBF);\n \/*\n[\n  'A', 'B', 'C',\n  'D', 'E', 'F',\n  'G', 'H', 'I'\n]\n*\/\nconsole.log(lettersDF);\n\/*\n[\n  'A', 'B', 'D',\n  'G', 'H', 'I',\n  'C', 'E', 'F'\n]\n*\/<\/code><\/pre>\n\n\n\n<p>\u4ee5\u4e0a\u70ba\u6700\u5ee3\u7fa9\u7684 tree \u7c21\u4ecb\uff0c\u901a\u5e38\u6bd4\u8f03\u591a\u61c9\u7528\u7684\u9084\u6709\u4e8c\u5143\u6a39\u3001\u7d05\u9ed1\u6a39\u7b49\u7b49\uff0c\u7559\u5f85\u4e4b\u5f8c\u7684\u6587\u7ae0\u4ecb\u7d39~<\/p>\n\n\n\n<h2><span class=\"ez-toc-section\" id=\"3_%E5%8F%83%E8%80%83%E8%B3%87%E6%96%99\"><\/span>3. \u53c3\u8003\u8cc7\u6599<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/www.books.com.tw\/products\/0010883039\" target=\"_blank\" rel=\"noreferrer noopener\">\u5927\u8a71\u8cc7\u6599\u7d50\u69cb(\u5168\u65b0\u5f69\u8272\u7248)<\/a><br><a href=\"https:\/\/www.udemy.com\/course\/coding-interview-bootcamp-algorithms-and-data-structure\/\" target=\"_blank\" rel=\"noreferrer noopener\">The Coding Interview Bootcamp: Algorithms + Data Structures<\/a><br><a href=\"http:\/\/alrightchiu.github.io\/SecondRound\/treeshu-introjian-jie.html\" target=\"_blank\" data-type=\"URL\" data-id=\"http:\/\/alrightchiu.github.io\/SecondRound\/treeshu-introjian-jie.html\" rel=\"noreferrer noopener\">Tree(\u6a39): Intro(\u7c21\u4ecb)<\/a><br><a href=\"https:\/\/chupai.github.io\/posts\/2006\/ds_tree_and_binary_tree\/\" target=\"_blank\" data-type=\"URL\" data-id=\"https:\/\/chupai.github.io\/posts\/2006\/ds_tree_and_binary_tree\/\" rel=\"noreferrer noopener\">JavaScript \u5b78\u6f14\u7b97\u6cd5\uff08\u5341\u4e8c\uff09- \u6a39 &amp; \u4e8c\u5143\u6a39<\/a><\/p>\n\n\n\n\n\n<p>\u5982\u679c\u89ba\u5f97\u6211\u7684\u6587\u7ae0\u6709\u5e6b\u52a9\u7684\u8a71\uff0c\u6b61\u8fce\u5e6b\u6211\u7684\u7c89\u5c08\u6309\u8b9a\u54e6~\u8b1d\u8b1d\u4f60\uff01<br><\/p>\n\n<iframe loading=\"lazy\" src=\"https:\/\/www.facebook.com\/plugins\/page.php?href=https%3A%2F%2Fwww.facebook.com%2Fjimmyswebnote&amp;tabs=timeline&amp;width=340&amp;height=500&amp;small_header=false&amp;adapt_container_width=true&amp;hide_cover=false&amp;show_facepile=true&amp;appId\" width=\"340\" height=\"500\" style=\"border:none;overflow:hidden\" scrolling=\"no\" frameborder=\"0\" allowfullscreen=\"true\" allow=\"autoplay; clipboard-write; encrypted-media; picture-in-picture; web-share\"><\/iframe>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tree \u662f\u6700\u5e38\u898b\u7684 non-linear data structure\uff0c\u69cb\u6210 tree \u7684\u57fa\u672c\u55ae\u4f4d\u70ba node\uff0c\u4ee5\u4e0b\u70ba tree \u7684\u5b9a\u7fa9<\/p>\n","protected":false},"author":1,"featured_media":2396,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[147,152],"tags":[164],"_links":{"self":[{"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/posts\/2386"}],"collection":[{"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/comments?post=2386"}],"version-history":[{"count":9,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/posts\/2386\/revisions"}],"predecessor-version":[{"id":2424,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/posts\/2386\/revisions\/2424"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/media\/2396"}],"wp:attachment":[{"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/media?parent=2386"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/categories?post=2386"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jimmyswebnote.com\/wp-json\/wp\/v2\/tags?post=2386"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}