{"id":66411,"date":"2023-12-19T03:34:48","date_gmt":"2023-12-18T19:34:48","guid":{"rendered":"https:\/\/docs.pingcode.com\/?p=66411"},"modified":"2023-12-19T03:34:57","modified_gmt":"2023-12-18T19:34:57","slug":"%e6%9c%80%e7%ae%80%e4%be%bf%e7%9a%84%e6%89%be%e5%ad%97%e7%ac%a6%e4%b8%b2%e4%b8%ad%e6%9c%80%e9%95%bf%e5%9b%9e%e6%96%87%e5%ad%90%e4%b8%b2%e7%9a%84%e6%96%b9%e6%b3%95%e6%98%af%e4%bb%80%e4%b9%88","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/66411.html","title":{"rendered":"\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5\u662f\u4ec0\u4e48"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote\">\n<p>\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5\u662f\u4e2d\u5fc3\u6269\u5c55\u6cd5\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u7684\u57fa\u672c\u601d\u60f3\u662f\u4ece\u5b57\u7b26\u4e32\u7684\u6bcf\u4e2a\u5b57\u7b26\u6216\u6bcf\u4e24\u4e2a\u5b57\u7b26\u4e4b\u95f4\u5f00\u59cb\uff0c\u4ee5\u5b83\u4eec\u4e3a\u4e2d\u5fc3\uff0c\u5411\u4e24\u8fb9\u6269\u5c55\uff0c\u67e5\u627e\u56de\u6587\u5b50\u4e32\u3002\u8fd9\u4e2a\u65b9\u6cd5\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(n^2)\uff0c\u5176\u4e2d n \u662f\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002\u5728\u6bcf\u4e2a\u4f4d\u7f6e\u4e0a\uff0c\u5b83\u90fd\u5c1d\u8bd5\u4ece\u4e2d\u5fc3\u6269\u5c55\u4ee5\u627e\u5230\u6700\u957f\u7684\u56de\u6587\u5b50\u4e32\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u3001\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5 <\/h2>\n\n\n\n<p>\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5\u662f\u4e2d\u5fc3\u6269\u5c55\u6cd5\u3002\u8fd9\u4e2a\u65b9\u6cd5\u7684\u57fa\u672c\u601d\u60f3\u662f\u4ece\u5b57\u7b26\u4e32\u7684\u6bcf\u4e2a\u5b57\u7b26\u6216\u6bcf\u4e24\u4e2a\u5b57\u7b26\u4e4b\u95f4\u5f00\u59cb\uff0c\u4ee5\u5b83\u4eec\u4e3a\u4e2d\u5fc3\uff0c\u5411\u4e24\u8fb9\u6269\u5c55\uff0c\u67e5\u627e\u56de\u6587\u5b50\u4e32\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e2a\u7b80\u5355\u7684Python\u793a\u4f8b\u4ee3\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>def longest_palindrome(s):\n    if not s or len(s) == 0:\n        return \"\"\n\n    start, end = 0, 0\n\n    for i in range(len(s)):\n        len1 = expand_around_center(s, i, i)  # \u4ee5\u5355\u4e2a\u5b57\u7b26\u4e3a\u4e2d\u5fc3\n        len2 = expand_around_center(s, i, i + 1)  # \u4ee5\u4e24\u4e2a\u5b57\u7b26\u4e3a\u4e2d\u5fc3\n        max_len = max(len1, len2)\n\n        if max_len &gt; end - start:\n            start = i - (max_len - 1) \/\/ 2\n            end = i + max_len \/\/ 2\n\n    return s&#091;start:end + 1]\n\ndef expand_around_center(s, left, right):\n    while left &gt;= 0 and right &lt; len(s) and s&#091;left] == s&#091;right]:\n        left -= 1\n        right += 1\n    return right - left - 1\n\n# \u793a\u4f8b\ninput_str = \"babad\"\nresult = longest_palindrome(input_str)\nprint(result)<\/code><\/pre>\n\n\n\n<p>\u8fd9\u4e2a\u65b9\u6cd5\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(n^2)\uff0c\u5176\u4e2d n \u662f\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002\u5728\u6bcf\u4e2a\u4f4d\u7f6e\u4e0a\uff0c\u5b83\u90fd\u5c1d\u8bd5\u4ece\u4e2d\u5fc3\u6269\u5c55\u4ee5\u627e\u5230\u6700\u957f\u7684\u56de\u6587\u5b50\u4e32\u3002\u8fd9\u662f\u4e00\u79cd\u7b80\u5355\u800c\u76f4\u89c2\u7684\u65b9\u6cd5\uff0c\u9002\u7528\u4e8e\u7406\u89e3\u56de\u6587\u5b50\u4e32\u7684\u57fa\u672c\u539f\u7406\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e8c\u3001\u4e2d\u5fc3\u6269\u5c55\u6cd5\u7684\u539f\u7406<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1. \u56de\u6587\u4e32\u7684\u4e2d\u5fc3<\/h3>\n\n\n\n<p>\u4e2d\u5fc3\u6269\u5c55\u6cd5\u7684\u7b2c\u4e00\u4e2a\u5173\u952e\u70b9\u662f\u7406\u89e3\u56de\u6587\u4e32\u7684\u4e2d\u5fc3\u3002\u56de\u6587\u4e32\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u5b57\u7b26\u4e32\uff0c\u5176\u7279\u70b9\u662f\u6b63\u5411\u548c\u53cd\u5411\u8bfb\u53d6\u65f6\u7ed3\u679c\u76f8\u540c\u3002\u5728\u4e2d\u5fc3\u6269\u5c55\u6cd5\u4e2d\uff0c\u6211\u4eec\u8003\u8651\u4ee5\u5b57\u7b26\u4e32\u7684\u6bcf\u4e2a\u5b57\u7b26\u6216\u6bcf\u4e24\u4e2a\u76f8\u90bb\u5b57\u7b26\u4e3a\u4e2d\u5fc3\uff0c\u5411\u4e24\u8fb9\u6269\u5c55\uff0c\u5bfb\u627e\u56de\u6587\u4e32\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. \u4e2d\u5fc3\u6269\u5c55\u8fc7\u7a0b<\/h3>\n\n\n\n<p>\u4e2d\u5fc3\u6269\u5c55\u8fc7\u7a0b\u662f\u6838\u5fc3\u6b65\u9aa4\uff0c\u5373\u4ece\u9009\u5b9a\u7684\u4e2d\u5fc3\u5f00\u59cb\uff0c\u5411\u5de6\u53f3\u4e24\u8fb9\u6269\u5c55\u3002\u6269\u5c55\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6bd4\u8f83\u5de6\u53f3\u4e24\u8fb9\u7684\u5b57\u7b26\u662f\u5426\u76f8\u7b49\u3002\u5982\u679c\u76f8\u7b49\uff0c\u8868\u793a\u56de\u6587\u4e32\u53ef\u4ee5\u7ee7\u7eed\u6269\u5c55\uff0c\u5426\u5219\u505c\u6b62\u6269\u5c55\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3. \u6269\u5c55\u7684\u65b9\u5411<\/h3>\n\n\n\n<p>\u56de\u6587\u4e32\u7684\u957f\u5ea6\u53ef\u80fd\u662f\u5947\u6570\uff0c\u4e5f\u53ef\u80fd\u662f\u5076\u6570\u3002\u56e0\u6b64\uff0c\u4e2d\u5fc3\u6269\u5c55\u7684\u65b9\u5411\u9700\u8981\u8003\u8651\u8fd9\u4e24\u79cd\u60c5\u51b5\u3002\u5f53\u56de\u6587\u4e32\u7684\u957f\u5ea6\u662f\u5947\u6570\u65f6\uff0c\u4e2d\u5fc3\u5b57\u7b26\u53ea\u6709\u4e00\u4e2a\uff0c\u5411\u4e24\u8fb9\u6269\u5c55\uff1b\u5f53\u957f\u5ea6\u662f\u5076\u6570\u65f6\uff0c\u4e2d\u5fc3\u5b57\u7b26\u6709\u4e24\u4e2a\uff0c\u540c\u65f6\u5411\u4e24\u8fb9\u6269\u5c55\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4. 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\u6269\u5c55\u7684\u7ec8\u6b62\u6761\u4ef6<\/h3>\n\n\n\n<p>\u4e2d\u5fc3\u6269\u5c55\u9700\u8981\u4e00\u4e2a\u7ec8\u6b62\u6761\u4ef6\u3002\u6269\u5c55\u7ec8\u6b62\u7684\u6761\u4ef6\u662f\u4e24\u8fb9\u7684\u5b57\u7b26\u4e0d\u76f8\u7b49\uff0c\u6216\u8005\u8fbe\u5230\u5b57\u7b26\u4e32\u7684\u8fb9\u754c\u3002\u8fd9\u65f6\u5019\uff0c\u6211\u4eec\u5c31\u5f97\u5230\u4e86\u4ee5\u9009\u5b9a\u4e2d\u5fc3\u4e3a\u57fa\u7840\u7684\u6700\u957f\u56de\u6587\u4e32\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6. \u5bfb\u627e\u6700\u957f\u56de\u6587\u4e32<\/h3>\n\n\n\n<p>\u4e2d\u5fc3\u6269\u5c55\u7684\u6700\u7ec8\u76ee\u6807\u662f\u5bfb\u627e\u6574\u4e2a\u5b57\u7b26\u4e32\u4e2d\u7684\u6700\u957f\u56de\u6587\u5b50\u4e32\u3002\u901a\u8fc7\u4e0d\u65ad\u66f4\u65b0\u6700\u957f\u56de\u6587\u4e32\u7684\u8d77\u59cb\u4f4d\u7f6e\u548c\u7ed3\u675f\u4f4d\u7f6e\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u6574\u4e2a\u8fc7\u7a0b\u4e2d\u7ef4\u62a4\u6700\u957f\u56de\u6587\u4e32\u7684\u4fe1\u606f\uff0c\u6700\u7ec8\u5f97\u5230\u6700\u4f18\u89e3\u3002<\/p>\n\n\n\n<p><img fetchpriority=\"high\" decoding=\"async\" width=\"484\" height=\"300\" src=\"https:\/\/cdn-docs.pingcode.com\/wp-content\/uploads\/2023\/12\/702900-\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5\u662f\u4ec0\u4e48.png?x-oss-process=image\/auto-orient,1\/format,webp\" class=\"aligncenter\" alt=\"\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5\u662f\u4ec0\u4e48\" 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&#8220;level&#8221; \u5305\u542b\u56de\u6587\u5b50\u4e32 &#8220;level&#8221;\u3002\u5728\u8fd9\u4e2a\u5b57\u7b26\u4e32\u4e2d\uff0c\u4ece\u5de6\u5230\u53f3\u6216\u4ece\u53f3\u5230\u5de6\u8bfb\u53d6\u90fd\u5f97\u5230\u76f8\u540c\u7684\u7ed3\u679c\uff0c\u56e0\u6b64 &#8220;level&#8221; \u662f\u4e00\u4e2a\u56de\u6587\u5b50\u4e32\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"\u6700\u7b80\u4fbf\u7684\u627e\u5b57\u7b26\u4e32\u4e2d\u6700\u957f\u56de\u6587\u5b50\u4e32\u7684\u65b9\u6cd5\u662f\u4e2d\u5fc3\u6269\u5c55\u6cd5\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u7684\u57fa\u672c\u601d\u60f3\u662f\u4ece\u5b57\u7b26\u4e32\u7684\u6bcf\u4e2a\u5b57\u7b26\u6216\u6bcf\u4e24\u4e2a\u5b57\u7b26\u4e4b\u95f4\u5f00\u59cb\uff0c [&hellip;]","protected":false},"author":4,"featured_media":66414,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[3938,3939,1708],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/66411"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=66411"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/66411\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/66414"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=66411"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=66411"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=66411"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}