{"id":567,"date":"2020-09-26T10:58:30","date_gmt":"2020-09-26T02:58:30","guid":{"rendered":"http:\/\/39.96.58.60\/?p=567"},"modified":"2022-10-18T16:38:45","modified_gmt":"2022-10-18T08:38:45","slug":"leetcode-234-%e5%9b%9e%e6%96%87%e9%93%be%e8%a1%a8","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=567","title":{"rendered":"Leetcode 234. \u56de\u6587\u94fe\u8868"},"content":{"rendered":"<p>\u8bf7\u5224\u65ad\u4e00\u4e2a\u94fe\u8868\u662f\u5426\u4e3a\u56de\u6587\u94fe\u8868\u3002<\/p>\n<p><strong>\u793a\u4f8b 1:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong> 1-&gt;2\n\n<strong>\u8f93\u51fa:<\/strong> false<\/pre>\n<p><strong>\u793a\u4f8b 2:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong> 1-&gt;2-&gt;2-&gt;1\n\n<strong>\u8f93\u51fa:<\/strong> true\n\n<\/pre>\n<p><strong>\u8fdb\u9636\uff1a<\/strong><\/p>\n<p>\u4f60\u80fd\u5426\u7528\u00a0O(n) \u65f6\u95f4\u590d\u6742\u5ea6\u548c O(1) \u7a7a\u95f4\u590d\u6742\u5ea6\u89e3\u51b3\u6b64\u9898\uff1f<\/p>\n<p>**\u96be\u5ea6**: Easy<\/p>\n<p>**\u6807\u7b7e**: \u94fe\u8868\u3001 \u53cc\u6307\u9488\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# Definition for singly-linked list.\n# class ListNode:\n#     def __init__(self, x):\n#         self.val = x\n#         self.next = None\n\n\"\"\"\n\u6267\u884c\u7528\u65f6\uff1a76 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8690.65% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a23.2 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8657.77% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u5feb\u6162\u6307\u9488\uff0c\u4f7f\u7528\u6162\u6307\u9488\u627e\u94fe\u8868\u4e2d\u5fc3\uff0c\u5c06\u540e\u534a\u90e8\u5206\u7ffb\u8f6c\n\"\"\"\nclass Solution:\n    def isPalindrome(self, head: ListNode) -&gt; bool:\n        fast, slow = head, head\n\n        while fast and fast.next:   # \u5feb\u6162\u6307\u9488\uff0c\u5feb\u6307\u9488\u662f\u6162\u6307\u9488\u76842\u500d\u901f,\u5f53\u5feb\u6307\u9488\u5230\u8fbe\u94fe\u8868\u672b\u5c3e\u65f6\uff0c\u6162\u6307\u9488\u521a\u597d\u5230\u4e00\u534a\n            fast = fast.next.next\n            slow = slow.next\n\n        reverse = None\n        while slow: # \u6162\u6307\u9488\u7ffb\u8f6c\u94fe\u8868\u540e\u534a\u90e8\u5206\n            i = slow\n            slow = slow.next\n            i.next = reverse\n            reverse = i\n\n        while head and reverse: # \u8fdb\u884c\u6bd4\u8f83\n            if head.val != reverse.val:\n                return False\n            head = head.next\n            reverse = reverse.next\n\n        return True<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u8bf7\u5224\u65ad\u4e00\u4e2a\u94fe\u8868\u662f\u5426\u4e3a\u56de\u6587\u94fe\u8868\u3002 \u793a\u4f8b 1: \u8f93\u5165: 1-&gt;2 \u8f93\u51fa: false \u793a\u4f8b 2: \u8f93\u5165: 1&#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\/567"}],"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=567"}],"version-history":[{"count":2,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/567\/revisions"}],"predecessor-version":[{"id":759,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/567\/revisions\/759"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=567"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=567"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}