{"id":64,"date":"2023-12-14T08:57:12","date_gmt":"2023-12-14T08:57:12","guid":{"rendered":"https:\/\/tensor.agenthub.uk\/?p=64"},"modified":"2024-04-19T10:54:07","modified_gmt":"2024-04-19T10:54:07","slug":"%e4%ba%8c%e5%8f%89%e6%a0%91%e7%9a%84%e9%81%8d%e5%8e%86","status":"publish","type":"post","link":"https:\/\/tensorzen.blog\/?p=64","title":{"rendered":"\u4e8c\u53c9\u6811\u7684\u904d\u5386"},"content":{"rendered":"\n<p>\u4e8c\u53c9\u6811\u7684\u904d\u5386\uff0c\u524d\u5e8f\uff0c\u4e2d\u5e8f\uff0c\u540e\u5e8f\u4e09\u79cd\uff0c\u4e09\u79cd\u904d\u5386\u65b9\u5f0f\uff0c\u5206\u522b\u7528BFS(Breadth First Search)\u548cDFS(Depth First Search)\u6765\u5b9e\u73b0\u4e0b\u3002<\/p>\n\n\n\n<p>DFS\u7b97\u6cd5\u6bd4\u8f83\u597d\u5b9e\u73b0\uff0c\u8fd9\u91cc\u8bb0\u5f55\u4e0bBFS\u7684\u5b9e\u73b0<\/p>\n\n\n\n<p>\u904d\u5386\u7684\u57fa\u672c\u7ed3\u6784\uff1a<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"while(root || !stk.empty()){\n    while(root){\n        stk.push(root);\n        root = root-&gt;left;\n    }\n    root = stk.top();\n    stk.pop();\n}\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root <\/span><span style=\"color: #81A1C1\">||<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">empty<\/span><span style=\"color: #ECEFF4\">()){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">push<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">left<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">top<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">pop<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #ECEFF4\">}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p><strong>\u524d\u5e8f\uff1a<\/strong><\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"\/**\n * Definition for a binary tree node.\n * struct TreeNode {\n *     int val;\n *     TreeNode *left;\n *     TreeNode *right;\n *     TreeNode() : val(0), left(nullptr), right(nullptr) {}\n *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}\n * };\n *\/\nclass Solution {\nprivate:\n    vector&lt;int&gt; result;\npublic:\n    void bfs(TreeNode* root){\n        if(!root) return;\n        stack&lt;TreeNode*&gt; stk;\n\n        while(root || !stk.empty()){\n            while(root){\n                stk.push(root);\n                result.emplace_back(root-&gt;val);\n                root = root-&gt;left;\n            }\n            root = stk.top();\n            stk.pop();\n            root = root-&gt;right;\n        }\n    }\n\n    vector&lt;int&gt; preorderTraversal(TreeNode* root) {\n        bfs(root);\n        return result;\n    }\n};\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #616E88\">\/**<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * Definition for a binary tree node.<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * struct TreeNode {<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     int val;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode *left;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode *right;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode() : val(0), left(nullptr), right(nullptr) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * };<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">class<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #8FBCBB\">Solution<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">private<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    vector<\/span><span style=\"color: #81A1C1\">&lt;int&gt;<\/span><span style=\"color: #D8DEE9FF\"> result<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">public<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #81A1C1\">void<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">bfs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">if<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">return;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        stack<\/span><span style=\"color: #81A1C1\">&lt;<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*&gt;<\/span><span style=\"color: #D8DEE9FF\"> stk<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root <\/span><span style=\"color: #81A1C1\">||<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">empty<\/span><span style=\"color: #ECEFF4\">()){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">push<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                <\/span><span style=\"color: #D8DEE9\">result<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">emplace_back<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">val<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">left<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">top<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">pop<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">right<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    vector<\/span><span style=\"color: #ECEFF4\">&lt;<\/span><span style=\"color: #81A1C1\">int<\/span><span style=\"color: #ECEFF4\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">preorderTraversal<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #88C0D0\">bfs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">return<\/span><span style=\"color: #D8DEE9FF\"> result<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #ECEFF4\">}<\/span><span style=\"color: #81A1C1\">;<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\u6211\u4eec\u62ff\u5230\u4e00\u4e2a\u8282\u70b9\u540e\u5c31\u5f80\u8fd9\u4e2a\u8282\u70b9\u7684\u5de6\u8fb9\u5f00\u59cb\u8bbf\u95ee\uff0c\u76f4\u5230\u8fd9\u4e2a\u8282\u70b9\u6ca1\u6709\u5de6\u8282\u70b9\u4e3a\u6b62\uff0c\u4ece\u4e8c\u53c9\u6811\u7684\u6784\u9020\u770b\uff0c\u9996\u6b21\u8bbf\u95ee\u5230\u67d0\u4e2a\u8282\u70b9\u8be5\u8282\u70b9\u5c31\u662f\u5b50\u6811\u7684\u6839\u8282\u70b9\uff0c\u524d\u5e8f\u4fbf\u5229\u6839\u8282\u70b9\u5c31\u5728\u524d\u9762\uff0c\u6240\u4ee5\u53ea\u8981\u8bbf\u95ee\u5230\u4e86\u8282\u70b9\u5c31\u7ed9\u4ed6\u653e\u8fdb\u7ed3\u679c\u91cc\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"while(root){\n    stk.push(root);\n    result.emplace_back(root-&gt;val);\n    root = root-&gt;left;\n}\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">push<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #D8DEE9\">result<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">emplace_back<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">val<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">left<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #ECEFF4\">}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\u5de6\u8fb9\u8def\u8bbf\u95ee\u5b8c\u6210\u540e\uff0c\u6808\u91cc\u9762\u88c5\u7684\u90fd\u662f\u5de6\u8fb9\u8def\u7684\u6839\u8282\u70b9\uff0c\u62ff\u5230\u5de6\u8fb9\u8def\u7684\u6700\u540e\u4e00\u4e2a\u8282\u70b9\uff0c\u5b83\u6ca1\u6709\u5de6\u8282\u70b9\uff0c\u83b7\u53d6\u53f3\u8282\u70b9\u3002\u5982\u679c\u53f3\u8282\u70b9\u7a7a\u7684\uff0c\u4f46\u662f\u6808\u91cc\u9762\u8fd8\u6709\u5176\u4ed6\u7684\u5de6\u8fb9\u8def\u7684\u8282\u70b9\uff0c\u6240\u4ee5\u5faa\u73af\u5f97\u7ee7\u7eed\uff0c\u8bbf\u95ee\u521a\u624d\u90a3\u4e2a\u5de6\u8fb9\u8def\u6700\u540e\u8282\u70b9\u7684\u7236\u8282\u70b9\uff0c\u6240\u4ee5\u770b\u5927\u5faa\u73af\u7684\u5224\u5b9a\u6761\u4ef6\u662f\uff1a<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"while(root || !stk.empty()){\n  ...\n  ...\n  ...\n}\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root <\/span><span style=\"color: #81A1C1\">||<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">empty<\/span><span style=\"color: #ECEFF4\">()){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  ...<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  ...<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">  ...<\/span><\/span>\n<span class=\"line\"><span style=\"color: #ECEFF4\">}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p><strong>\u4e2d\u5e8f<\/strong><\/p>\n\n\n\n<p>\u8fd9\u91cc\u6709\u4e2a\u7591\u95ee\u4e3a\u4ec0\u4e48\u524d\u5e8f\u548c\u4e2d\u5e8f\u53ea\u662f\u632a\u52a8\u4e00\u4e0b\u8f93\u51fa\u8282\u70b9\u7684\u4f4d\u7f6e\u5c31\u53ef\u4ee5\u5b9e\u73b0\uff0c\u4e3b\u8981\u662f\u56e0\u4e3a\uff0c\u4e0d\u7ba1\u524d\u5e8f\u8fd8\u662f\u4e2d\u5e8f\uff0c\u90fd\u662f\u5148\u628a\u5de6\u8fb9\u8def\u5148\u5165\u6808\uff0c\u5728\u4e00\u6761\u5de6\u8fb9\u8def\u8bbf\u95ee\u7ed3\u675f\u540e\uff0c\u5224\u5b9a\u6808\u9876\u5143\u7d20\u662f\u4e0d\u662f\u6709\u53f3\u8282\u70b9\uff0c\u5982\u679c\u6709\u53f3\u8282\u70b9\uff0c\u8fdb\u5165\u53e6\u4e00\u4e2a\u5faa\u73af\uff0c\u5f00\u59cb\u5faa\u73af\u53f3\u8282\u70b9\u7684\u5de6\u8fb9\u8def\uff0c\u5982\u679c\u5728\u8bbf\u95ee\u53f3\u8282\u70b9\u524d\u628a\u8be5\u8282\u70b9\u8f93\u51fa\uff0c\u90a3\u4e48\u5c31\u662f\u524d\u5e8f\u548c\u4e2d\u5e8f\u4e86\uff0c\u8bbf\u95ee\u4e4b\u540e\u5c31\u662f\u540e\u7eed\u3002\u600e\u4e48\u533a\u5206\u524d\u5e8f\u548c\u4e2d\u5e8f\uff1f\u4e0d\u77e5\u9053\uff5e\u80cc\u8fc7\u7684\uff5e\uff5e\u9057\u61be<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"\/**\n * Definition for a binary tree node.\n * struct TreeNode {\n *     int val;\n *     TreeNode *left;\n *     TreeNode *right;\n *     TreeNode() : val(0), left(nullptr), right(nullptr) {}\n *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}\n * };\n *\/\nclass Solution {\npublic:\n    void bfs(TreeNode* root){\n        if(!root) return;\n        stack&lt;TreeNode*&gt; stk;\n        while(root || !stk.empty()){\n            while(root){\n                stk.push(root);\n                root = root-&gt;left;\n            }\n            root = stk.top();\n            result.emplace_back(root-&gt;val);\n            stk.pop();\n            root = root-&gt;right;\n        }\n    }\n    vector&lt;int&gt; inorderTraversal(TreeNode* root) {\n        bfs(root);\n        return result;\n    }\nprivate:\n    vector&lt;int&gt; result;\n};\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #616E88\">\/**<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * Definition for a binary tree node.<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * struct TreeNode {<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     int val;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode *left;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode *right;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode() : val(0), left(nullptr), right(nullptr) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * };<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">class<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #8FBCBB\">Solution<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">public<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #81A1C1\">void<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">bfs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">if<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">return;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        stack<\/span><span style=\"color: #81A1C1\">&lt;<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*&gt;<\/span><span style=\"color: #D8DEE9FF\"> stk<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root <\/span><span style=\"color: #81A1C1\">||<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">empty<\/span><span style=\"color: #ECEFF4\">()){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">push<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">left<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">top<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #D8DEE9\">result<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">emplace_back<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">val<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">pop<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">right<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    vector<\/span><span style=\"color: #ECEFF4\">&lt;<\/span><span style=\"color: #81A1C1\">int<\/span><span style=\"color: #ECEFF4\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">inorderTraversal<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #88C0D0\">bfs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">return<\/span><span style=\"color: #D8DEE9FF\"> result<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">private<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    vector<\/span><span style=\"color: #81A1C1\">&lt;int&gt;<\/span><span style=\"color: #D8DEE9FF\"> result<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #ECEFF4\">}<\/span><span style=\"color: #81A1C1\">;<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\u8ddf\u524d\u5e8f\u7684\u4e0d\u540c\u70b9\u5c31\u662f\u5728\u4ec0\u4e48\u65f6\u5019\u8f93\u51fa\u8282\u70b9\uff0c\u524d\u5e8f\u662f\u5728\u5165\u6808\u67d0\u4e2a\u8282\u70b9\u7684\u65f6\u5019\u76f4\u63a5\u8f93\u51fa\u4e86\uff0c\u4e2d\u5e8f\u662f\u5728\u51fa\u6808\u7684\u65f6\u5019\u8f93\u51fa\u3002<\/p>\n\n\n\n<p><strong>\u540e\u5e8f<\/strong><\/p>\n\n\n\n<p>\u8fd9\u4e2a\u540e\u5e8f\u6bd4\u8f83\u9ebb\u70e6\uff0c\u53cd\u6b63\u6211\u662f\u80cc\u8fc7\u4e86\uff0c\u57fa\u4e8e\u4e0a\u9762\u7684\u5206\u6790\uff0c\u5fc5\u7136\u662f\u5728\u8bbf\u95ee\u8be5\u8282\u70b9\u7684\u53f3\u8282\u70b9\u4e4b\u540e\u8f93\u51fa\u8be5\u8282\u70b9\u7684\uff0c\u5982\u679c\u8be5\u8282\u70b9\u672c\u8eab\u5c31\u662f\u53f6\u5b50\u8282\u70b9\uff0c\u53f3\u8282\u70b9\u80af\u5b9a\u662f\u7a7a\uff0c\u8fd9\u4e2a\u65f6\u5019\u53ef\u4ee5\u8f93\u51fa\u8be5\u8282\u70b9\uff0c\u95ee\u9898\u662f\u600e\u4e48\u5224\u5b9a\u8be5\u8282\u70b9\u7684\u53f3\u5b50\u6811\u5df2\u7ecf\u8bbf\u95ee\u5b8c\u4e86\uff0c\u4ece\u80cc\u7684\u7b54\u6848\u91cc\u77e5\u9053\uff0c\u5982\u679c\u8fd9\u4e2a\u8282\u70b9\u6709\u53f3\u8282\u70b9\uff0c\u5f97\u628a\u8be5\u8282\u70b9\u4fdd\u5b58\u4e00\u4e0b\uff0c\u7b49\u628a\u4ed6\u53f3\u8fb9\u7684\u8282\u70b9\u90fd\u8f93\u51fa\u5b8c\u4e86\u518d\u628a\u5b58\u50a8\u7684\u8fd9\u4e2a\u8be5\u8282\u70b9\u8f93\u51fa\u3002\u95ee\u9898\u5c31\u662f\u600e\u4e48\u77e5\u9053\u8bbf\u95ee\u5b8c\u4e86\uff0c\u8fd9\u4e48\u8bf4\u4e0d\u5927\u660e\u786e\uff0c\u5e94\u8be5\u662f\u8bf4\u8bbf\u95ee\u5b8c\u4e86\u4e4b\u540e\uff0c\u600e\u4e48\u56de\u5230\u8fd9\u4e2a\u8be5\u8282\u70b9\uff0c\u5e94\u4e3a\u53d8\u91cfroot\u7a7a\u4e86\u4ee5\u540e\u4f1a\u76f4\u63a5\u4ecestk\u51fa\u6808\uff0c\u56e0\u4e3a\u5de6\u8fb9\u8def\u7684\u8282\u70b9\u90fd\u5728\u6808\u91cc\u9762\uff0c\u8be5\u8282\u70b9\u7684\u7236\u8282\u70b9\u5176\u5b9e\u5c31\u662fstk\u4e2dtop\u7684\u8282\u70b9\uff0c\u6240\u4ee5top\u8282\u70b9\u7684\u53f3\u8282\u70b9\u5982\u679c\u7b49\u4e8e\u6211\u4eec\u5b58\u50a8\u7684\u8be5\u8282\u70b9\uff0c\u5c31\u8bf4\u660e\u56de\u6765\u4e86\uff0c\u56de\u6765\u4e86\u5c31\u53ef\u4ee5\u8bbf\u95ee\u8be5\u5b58\u50a8\u7684\u8282\u70b9\u4e86\u3002\u6240\u4ee5\u5224\u5b9a\u662f\u5426\u8f93\u51fa\uff0c\u5c31\u662f\u5f53\u8be5\u8282\u70b9\u6ca1\u6709\u53f3\u8282\u70b9\uff0c\u6216\u8005\u5b58\u50a8\u7684\u8282\u70b9\u7b49\u4e8e\u6808\u9876\u8282\u70b9\u7684\u53f3\u8282\u70b9\uff0c\u53ef\u4ee5\u8f93\u51fa\u3002\u5982\u679c\u4e0d\u662f\u5462\uff1f\u5f53\u524d\u8282\u70b9\u6709\u53f3\u8282\u70b9\uff0c\u5f97\u53bb\u8bbf\u95ee\u53f3\u8282\u70b9\uff0c\u8be5\u8282\u70b9\u5f97\u5165\u6808\uff1b\u7b2c\u4e8c\u79cd\u53ef\u80fd\u4e0d\u77e5\u9053\uff5e\u80cc\u8fc7<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"\/**\n * Definition for a binary tree node.\n * struct TreeNode {\n *     int val;\n *     TreeNode *left;\n *     TreeNode *right;\n *     TreeNode() : val(0), left(nullptr), right(nullptr) {}\n *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}\n * };\n *\/\nclass Solution {\npublic:\n    void bfs(TreeNode* root){\n        if(!root) return;\n        TreeNode* prev;\n        stack&lt;TreeNode*&gt; stk;\n        while(root || !stk.empty()){\n            while(root){\n                stk.push(root);\n                root = root-&gt;left;\n            }\n            root = stk.top();\n            stk.pop();\n            if(!root-&gt;right || prev == root-&gt;right){\n                result.emplace_back(root-&gt;val);\n                prev = root;\n                root = nullptr;\n            }else{\n                stk.push(root);\n                root = root-&gt;right;\n            }\n        }\n        \n    }\n    vector&lt;int&gt; postorderTraversal(TreeNode* root) {\n        bfs(root);\n        return result;\n    }\nprivate:\n    vector&lt;int&gt; result;\n};\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #616E88\">\/**<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * Definition for a binary tree node.<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * struct TreeNode {<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     int val;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode *left;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode *right;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode() : val(0), left(nullptr), right(nullptr) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> * };<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\"> *\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">class<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #8FBCBB\">Solution<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">public<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #81A1C1\">void<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">bfs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">if<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">return;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> prev<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        stack<\/span><span style=\"color: #81A1C1\">&lt;<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*&gt;<\/span><span style=\"color: #D8DEE9FF\"> stk<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root <\/span><span style=\"color: #81A1C1\">||<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">empty<\/span><span style=\"color: #ECEFF4\">()){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #81A1C1\">while<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">push<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">left<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">top<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">pop<\/span><span style=\"color: #ECEFF4\">()<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #81A1C1\">if<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #81A1C1\">!<\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">right<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">||<\/span><span style=\"color: #D8DEE9FF\"> prev <\/span><span style=\"color: #81A1C1\">==<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">right<\/span><span style=\"color: #ECEFF4\">){<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                <\/span><span style=\"color: #D8DEE9\">result<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">emplace_back<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">val<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                prev <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> root<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #81A1C1\">nullptr;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #ECEFF4\">}<\/span><span style=\"color: #81A1C1\">else<\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                <\/span><span style=\"color: #D8DEE9\">stk<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">push<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">                root <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">-&gt;<\/span><span style=\"color: #D8DEE9\">right<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">            <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    vector<\/span><span style=\"color: #ECEFF4\">&lt;<\/span><span style=\"color: #81A1C1\">int<\/span><span style=\"color: #ECEFF4\">&gt;<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">postorderTraversal<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">TreeNode<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #D8DEE9\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #ECEFF4\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #88C0D0\">bfs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">root<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">        <\/span><span style=\"color: #81A1C1\">return<\/span><span style=\"color: #D8DEE9FF\"> result<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    <\/span><span style=\"color: #ECEFF4\">}<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">private<\/span><span style=\"color: #ECEFF4\">:<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">    vector<\/span><span style=\"color: #81A1C1\">&lt;int&gt;<\/span><span style=\"color: #D8DEE9FF\"> result<\/span><span style=\"color: #81A1C1\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #ECEFF4\">}<\/span><span style=\"color: #81A1C1\">;<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\u53cd\u6b63\u5c31\u8fd9\u4e48\u5199\uff0c\u5c31\u53ef\u4ee5\u4e86\uff5e\u4e0d\u8981\u8bd5\u56fe\u7406\u89e3\u5b83\uff0c\u611f\u53d7\u5b83\uff0c\u80cc\u8fc7\u5b83\uff5e\uff5e\uff5e<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u524d\u5e8f\u3001\u4e2d\u5e8f\u3001\u540e\u5e8f\u904d\u5386\u4e8c\u53c9\u6811\uff0c\u8fed\u4ee3\u6cd5\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,17],"tags":[],"class_list":["post-64","post","type-post","status-publish","format-standard","hentry","category-coding","category-leetcode"],"_links":{"self":[{"href":"https:\/\/tensorzen.blog\/index.php?rest_route=\/wp\/v2\/posts\/64","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tensorzen.blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tensorzen.blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tensorzen.blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tensorzen.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=64"}],"version-history":[{"count":3,"href":"https:\/\/tensorzen.blog\/index.php?rest_route=\/wp\/v2\/posts\/64\/revisions"}],"predecessor-version":[{"id":278,"href":"https:\/\/tensorzen.blog\/index.php?rest_route=\/wp\/v2\/posts\/64\/revisions\/278"}],"wp:attachment":[{"href":"https:\/\/tensorzen.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=64"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tensorzen.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=64"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tensorzen.blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=64"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}