{"id":351,"date":"2025-09-03T17:28:51","date_gmt":"2025-09-03T09:28:51","guid":{"rendered":"https:\/\/heyingnian.com\/?p=351"},"modified":"2025-09-03T17:29:22","modified_gmt":"2025-09-03T09:29:22","slug":"leetcode-206","status":"publish","type":"post","link":"https:\/\/heyingnian.com\/index.php\/2025\/09\/03\/leetcode-206\/","title":{"rendered":"\u53cd\u8f6c\u94fe\u8868"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">\ud83d\udd17 \u53cd\u8f6c\u94fe\u8868<\/h1>\n\n\n\n<p>\u9898\u76ee\u6765\u6e90\uff1a<a target=\"_blank\" rel=\"noreferrer noopener\"><a href=\"https:\/\/leetcode.cn\/problems\/reverse-linked-list\/description\/?envType=study-plan-v2&amp;envId=top-100-liked\" target=\"_blank\" rel=\"noopener\">206. \u53cd\u8f6c\u94fe\u8868 &#8211; \u529b\u6263\uff08LeetCode\uff09<\/a><\/a><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83d\udccc \u9898\u76ee\u63cf\u8ff0<\/p>\n\n\n\n<p>\u7ed9\u4f60\u5355\u94fe\u8868\u7684\u5934\u8282\u70b9 <code>head<\/code>\uff0c\u8bf7\u4f60<strong>\u53cd\u8f6c\u94fe\u8868<\/strong>\uff0c\u5e76\u8fd4\u56de\u53cd\u8f6c\u540e\u7684\u94fe\u8868\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u53cd\u8f6c<\/strong>\uff1a\u5c06\u94fe\u8868\u4ece\u00a0<code>A \u2192 B \u2192 C \u2192 D<\/code>\u00a0\u53d8\u4e3a\u00a0<code>D \u2192 C \u2192 B \u2192 A<\/code>\u3002<\/li>\n\n\n\n<li>\u82e5\u94fe\u8868\u4e3a\u7a7a\u6216\u53ea\u6709\u4e00\u4e2a\u8282\u70b9\uff0c\u8fd4\u56de\u5176\u672c\u8eab\u3002<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u2705 \u793a\u4f8b\u89e3\u6790<\/p>\n\n\n\n<p><strong>\u793a\u4f8b 1<\/strong>\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-13.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"542\" height=\"222\" data-original=\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-13.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-353\"  sizes=\"auto, (max-width: 542px) 100vw, 542px\" \/><\/div><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>head = [1,2,3,4,5]<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>[5,4,3,2,1]<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a\u539f\u94fe\u8868\u00a0<code>1\u21922\u21923\u21924\u21925<\/code>\uff0c\u53cd\u8f6c\u540e\u53d8\u4e3a\u00a0<code>5\u21924\u21923\u21922\u21921<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p><strong>\u793a\u4f8b 2<\/strong>\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-14.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"182\" height=\"222\" data-original=\"https:\/\/heyingnian.com\/wp-content\/uploads\/2025\/09\/image-14.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-354\"\/><\/div><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>head = [1,2]<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>[2,1]<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a<code>1\u21922<\/code>\u00a0\u53d8\u4e3a\u00a0<code>2\u21921<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p><strong>\u793a\u4f8b 3<\/strong>\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8f93\u5165\uff1a<code>head = []<\/code><\/li>\n\n\n\n<li>\u8f93\u51fa\uff1a<code>[]<\/code><\/li>\n\n\n\n<li>\u89e3\u91ca\uff1a\u7a7a\u94fe\u8868\u53cd\u8f6c\u540e\u4ecd\u4e3a\u7a7a\u3002<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\u26a0\ufe0f \u63d0\u793a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u94fe\u8868\u4e2d\u8282\u70b9\u7684\u6570\u76ee\u8303\u56f4\u662f\u00a0<code>[0, 5000]<\/code><\/li>\n\n\n\n<li><code>-5000 &lt;= Node.val &lt;= 5000<\/code><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83d\udca1 \u89e3\u6cd5\uff1a\u8fed\u4ee3\u6cd5\uff08\u4e09\u6307\u9488\uff09\u2014\u2014 O(n) \u65f6\u95f4\uff0cO(1) \u7a7a\u95f4<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Solution {\n    public ListNode reverseList(ListNode head) {\n        if (head == null || head.next == null) {\n            return head;\n        }\n        ListNode res = null; \/\/ \u6307\u5411\u5df2\u53cd\u8f6c\u90e8\u5206\u7684\u5934\u8282\u70b9\n        while (head != null) {\n            ListNode next = head.next; \/\/ \u4fdd\u5b58\u4e0b\u4e00\u4e2a\u8282\u70b9\n            head.next = res;           \/\/ \u5f53\u524d\u8282\u70b9\u6307\u5411\u524d\u4e00\u6bb5\u53cd\u8f6c\u94fe\u8868\n            res = head;                \/\/ \u66f4\u65b0\u53cd\u8f6c\u94fe\u8868\u7684\u5934\n            head = next;               \/\/ \u79fb\u52a8\u5230\u539f\u94fe\u8868\u7684\u4e0b\u4e00\u4e2a\u8282\u70b9\n        }\n        return res;\n    }\n}<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83d\udcca \u590d\u6742\u5ea6\u5206\u6790<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u65f6\u95f4\u590d\u6742\u5ea6\uff1aO(n)<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u6bcf\u4e2a\u8282\u70b9\u88ab\u8bbf\u95ee\u4e14\u4ec5\u88ab\u8bbf\u95ee\u4e00\u6b21\uff0c\u603b\u5171\u00a0<code>n<\/code>\u00a0\u4e2a\u8282\u70b9\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u7a7a\u95f4\u590d\u6742\u5ea6\uff1aO(1)<\/strong> \u2705\n<ul class=\"wp-block-list\">\n<li>\u4ec5\u4f7f\u7528\u5e38\u6570\u4e2a\u989d\u5916\u6307\u9488\uff1a<code>res<\/code>\u3001<code>next<\/code>\u3001<code>head<\/code>\u3002<\/li>\n\n\n\n<li>\u65e0\u9012\u5f52\u8c03\u7528\u6808\uff0c\u7a7a\u95f4\u6548\u7387\u6781\u9ad8\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud83e\udde9 \u89e3\u9898\u601d\u8def<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6838\u5fc3\u601d\u60f3\uff1a\u8fb9\u904d\u5386\u8fb9\u53cd\u8f6c\uff0c\u7ef4\u62a4\u201c\u5df2\u53cd\u8f6c\u201d\u90e8\u5206\u7684\u5934\u8282\u70b9<\/strong>\n<ul class=\"wp-block-list\">\n<li>\u4f7f\u7528\u4e09\u4e2a\u5173\u952e\u53d8\u91cf\uff1a\n<ul class=\"wp-block-list\">\n<li><code>head<\/code>\uff1a\u6307\u5411\u539f\u94fe\u8868\u5f53\u524d\u5f85\u5904\u7406\u7684\u8282\u70b9\u3002<\/li>\n\n\n\n<li><code>res<\/code>\uff1a\u6307\u5411<strong>\u5df2\u53cd\u8f6c\u90e8\u5206<\/strong>\u7684\u5934\u8282\u70b9\uff08\u521d\u59cb\u4e3a\u00a0<code>null<\/code>\uff09\u3002<\/li>\n\n\n\n<li><code>next<\/code>\uff1a\u4e34\u65f6\u4fdd\u5b58\u00a0<code>head.next<\/code>\uff0c\u9632\u6b62\u65ad\u94fe\u540e\u4e22\u5931\u540e\u7eed\u8282\u70b9\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u53cd\u8f6c\u6b65\u9aa4\uff08\u6bcf\u8f6e\u64cd\u4f5c\uff09<\/strong>\uff1ajava\u6df1\u8272\u7248\u672c<code>ListNode next = head.next; \/\/ 1. \u4fdd\u5b58\u4e0b\u4e00\u4e2a\u8282\u70b9 head.next = res; \/\/ 2. \u5f53\u524d\u8282\u70b9\u6307\u5411\u524d\u4e00\u6bb5\u53cd\u8f6c\u94fe\u8868 res = head; \/\/ 3. \u66f4\u65b0\u53cd\u8f6c\u94fe\u8868\u7684\u5934\u4e3a\u5f53\u524d\u8282\u70b9 head = next; \/\/ 4. \u79fb\u52a8\u5230\u539f\u94fe\u8868\u7684\u4e0b\u4e00\u4e2a\u8282\u70b9<\/code>\u8fd9\u56db\u6b65\u5b9e\u73b0\u4e86\u6307\u9488\u7684\u201c\u7ffb\u8f6c\u201d\u548c\u201c\u63a8\u8fdb\u201d\u3002<\/li>\n\n\n\n<li><strong>\u4e3e\u4f8b\u8bf4\u660e<\/strong>\uff1a<br>\u5bf9 <code>head = [1,2,3,4,5]<\/code>\uff1a\u6b65\u9aa4headresnext\u64cd\u4f5c\u521d\u59cb1\u21922\u21923\u21924\u21925null&#8211;11\u2192&#8230;null2\u21923\u21924\u21925<code>1.next = null<\/code>,\u00a0<code>res = 1<\/code>,\u00a0<code>head = 2<\/code>22\u2192&#8230;1\u2192null3\u21924\u21925<code>2.next = 1<\/code>,\u00a0<code>res = 2<\/code>,\u00a0<code>head = 3<\/code>33\u2192&#8230;2\u21921\u2192null4\u21925<code>3.next = 2<\/code>,\u00a0<code>res = 3<\/code>,\u00a0<code>head = 4<\/code>44\u2192&#8230;3\u21922\u21921\u2192null5<code>4.next = 3<\/code>,\u00a0<code>res = 4<\/code>,\u00a0<code>head = 5<\/code>55\u2192&#8230;4\u21923\u21922\u21921\u2192nullnull<code>5.next = 4<\/code>,\u00a0<code>res = 5<\/code>,\u00a0<code>head = null<\/code>\u7ed3\u675fnull5\u21924\u21923\u21922\u21921\u2192null-\u8fd4\u56de\u00a0<code>res<\/code>\u00a0\u2705<\/li>\n\n\n\n<li><strong>\u8fb9\u754c\u5904\u7406<\/strong>\uff1a\n<ul class=\"wp-block-list\">\n<li>\u7a7a\u94fe\u8868\uff1a<code>head == null<\/code>\uff0c\u76f4\u63a5\u8fd4\u56de\u00a0<code>null<\/code>\u3002<\/li>\n\n\n\n<li>\u5355\u8282\u70b9\uff1a<code>head.next == null<\/code>\uff0c\u76f4\u63a5\u8fd4\u56de\u00a0<code>head<\/code>\u3002<\/li>\n\n\n\n<li>\u591a\u8282\u70b9\uff1a\u5faa\u73af\u5904\u7406\u76f4\u5230\u00a0<code>head == null<\/code>\u3002<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u4e3a\u4ec0\u4e48 <code>res<\/code> \u6700\u7ec8\u662f\u65b0\u5934\uff1f<\/strong>\n<ul class=\"wp-block-list\">\n<li><code>res<\/code>\u00a0\u59cb\u7ec8\u6307\u5411<strong>\u5df2\u53cd\u8f6c\u94fe\u8868\u7684\u5934\u8282\u70b9<\/strong>\u3002<\/li>\n\n\n\n<li>\u6bcf\u6b21\u5c06\u00a0<code>head<\/code>\u00a0\u63d2\u5165\u5230\u00a0<code>res<\/code>\u00a0\u524d\u9762\uff0c<code>res<\/code>\u00a0\u5c31\u66f4\u65b0\u4e3a\u65b0\u7684\u5934\u3002<\/li>\n\n\n\n<li>\u6700\u7ec8\u00a0<code>res<\/code>\u00a0\u6307\u5411\u539f\u94fe\u8868\u7684\u6700\u540e\u4e00\u4e2a\u8282\u70b9\uff0c\u5373\u65b0\u94fe\u8868\u7684\u5934\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udd17 \u53cd\u8f6c\u94fe\u8868 \u9898\u76ee\u6765\u6e90\uff1a206. \u53cd\u8f6c\u94fe\u8868 &#8211; \u529b\u6263\uff08LeetCode\uff09 \ud83d\udccc \u9898\u76ee\u63cf\u8ff0 \u7ed9\u4f60\u5355\u94fe\u8868 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,38],"tags":[14,51],"class_list":["post-351","post","type-post","status-publish","format-standard","hentry","category-algorithm","category-linked_list","tag-algorithm","tag-linked_list"],"_links":{"self":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/351","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/comments?post=351"}],"version-history":[{"count":2,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/351\/revisions"}],"predecessor-version":[{"id":355,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/posts\/351\/revisions\/355"}],"wp:attachment":[{"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/media?parent=351"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/categories?post=351"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/heyingnian.com\/index.php\/wp-json\/wp\/v2\/tags?post=351"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}