{"id":639,"date":"2020-09-26T11:06:12","date_gmt":"2020-09-26T03:06:12","guid":{"rendered":"http:\/\/39.96.58.60\/?p=639"},"modified":"2022-10-18T16:38:35","modified_gmt":"2022-10-18T08:38:35","slug":"leetcode-143-%e9%87%8d%e6%8e%92%e9%93%be%e8%a1%a8","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=639","title":{"rendered":"Leetcode 143. \u91cd\u6392\u94fe\u8868"},"content":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u5355\u94fe\u8868&nbsp;<em>L<\/em>\uff1a<em>L<\/em><sub>0<\/sub>\u2192<em>L<\/em><sub>1<\/sub>\u2192\u2026\u2192<em>L<\/em><sub><em>n<\/em>-1<\/sub>\u2192<em>L<\/em><sub>n \uff0c<\/sub><br \/>\n\u5c06\u5176\u91cd\u65b0\u6392\u5217\u540e\u53d8\u4e3a\uff1a <em>L<\/em><sub>0<\/sub>\u2192<em>L<\/em><sub><em>n<\/em><\/sub>\u2192<em>L<\/em><sub>1<\/sub>\u2192<em>L<\/em><sub><em>n<\/em>-1<\/sub>\u2192<em>L<\/em><sub>2<\/sub>\u2192<em>L<\/em><sub><em>n<\/em>-2<\/sub>\u2192\u2026<\/p>\n<p>\u4f60\u4e0d\u80fd\u53ea\u662f\u5355\u7eaf\u7684\u6539\u53d8\u8282\u70b9\u5185\u90e8\u7684\u503c\uff0c\u800c\u662f\u9700\u8981\u5b9e\u9645\u7684\u8fdb\u884c\u8282\u70b9\u4ea4\u6362\u3002<\/p>\n<p><strong>\u793a\u4f8b&nbsp;1:<\/strong><\/p>\n<pre>\u7ed9\u5b9a\u94fe\u8868 1-&gt;2-&gt;3-&gt;4, \u91cd\u65b0\u6392\u5217\u4e3a 1-&gt;4-&gt;2-&gt;3.<\/pre>\n<p><strong>\u793a\u4f8b 2:<\/strong><\/p>\n<pre>\u7ed9\u5b9a\u94fe\u8868 1-&gt;2-&gt;3-&gt;4-&gt;5, \u91cd\u65b0\u6392\u5217\u4e3a 1-&gt;5-&gt;2-&gt;4-&gt;3.<\/pre>\n<p>**\u96be\u5ea6**: Medium<\/p>\n<p>**\u6807\u7b7e**: \u94fe\u8868\u3001<\/p>\n<div class=\"hcb_wrap\">\n<pre class=\"prism undefined-numbers lang-python\" data-lang=\"Python\"><code>\n# -*- coding: utf-8 -*-\n# @Author  : LG\n\n\"\"\"\n\u6267\u884c\u7528\u65f6\uff1a88 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8699.84% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a22.7 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8632.31% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u5148\u524d\u540e\u4e24\u90e8\u5206\u65ad\u5f00\u94fe\u8868\uff0c\u5c06\u540e\u534a\u90e8\u5206\u53cd\u8f6c\u540e\uff0c\u4e00\u4e00\u63d2\u5165\u524d\u534a\u90e8\u5206\n\"\"\"\nclass Solution:\n    def reorderList(self, head: ListNode) -&gt; None:\n        \"\"\"\n        Do not return anything, modify head in-place instead.\n        \"\"\"\n        if not (head and head.next and head.next.next): # \u5982\u679c\u94fe\u8868\u957f\u5ea6\u5c0f\u4e8e3\uff0c\u76f4\u63a5\u8fd4\u56de\u5f53\u524d\u94fe\u8868\n            return\n\n        s, f = head, head   # \u5feb\u6162\u6307\u9488\uff0c\u65ad\u5f00\u94fe\u8868\n        while f and f.next:\n            s = s.next\n            f = f.next.next\n\n        p = s.next  # \u9700\u8981\u7ffb\u8f6c\u7684\u540e\u534a\u6bb5\u94fe\u8868\u7684\u5934\n        q = p.next  # q\u6307\u5411p\u7684\u4e0b\u4e00\u4e2a\u8282\u70b9\n        p.next = None   # \u65ad\u5f00p\u8282\u70b9\uff0c\u4e0d\u7136\u53cd\u8f6c\u540e\u7684\u540e\u534a\u6bb5\u4f1a\u5b58\u5728\u73af\n        s.next = None   # \u65ad\u5f00\u94fe\u8868\n\n        while q:    # \u53cd\u8f6c\u94fe\u8868\n            r = q.next\n            q.next = p\n            p = q\n            q = r\n\n        h = head\n        while p:    # \u5c06\u7ffb\u8f6c\u540e\u7684\u540e\u534a\u6bb5\u94fe\u8868\uff0c\u4e00\u4e00\u63d2\u5165\u524d\u534a\u6bb5\u94fe\u8868\u4e2d\n            h_next = h.next\n            p_next = p.next\n            h.next = p\n            p.next = h_next\n            h = h_next\n            p = p_next<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u5355\u94fe\u8868&nbsp;L\uff1aL0\u2192L1\u2192\u2026\u2192Ln-1\u2192Ln \uff0c \u5c06\u5176\u91cd\u65b0\u6392\u5217\u540e\u53d8\u4e3a\uff1a L0\u2192Ln\u2192L1\u2192Ln&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":[],"categories":[11,1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/639"}],"collection":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=639"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/639\/revisions"}],"predecessor-version":[{"id":640,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/639\/revisions\/640"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=639"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=639"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=639"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}