{"id":443,"date":"2020-09-26T10:42:13","date_gmt":"2020-09-26T02:42:13","guid":{"rendered":"http:\/\/39.96.58.60\/?p=443"},"modified":"2022-10-18T16:39:15","modified_gmt":"2022-10-18T08:39:15","slug":"leetcode-28-%e5%ae%9e%e7%8e%b0-strstr","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=443","title":{"rendered":"Leetcode 28. \u5b9e\u73b0 strStr()"},"content":{"rendered":"<p>\u5b9e\u73b0&nbsp;<a href=\"https:\/\/baike.baidu.com\/item\/strstr\/811469\" target=\"_blank\" rel=\"noopener noreferrer\">strStr()<\/a>&nbsp;\u51fd\u6570\u3002<\/p>\n<p>\u7ed9\u5b9a\u4e00\u4e2a&nbsp;haystack \u5b57\u7b26\u4e32\u548c\u4e00\u4e2a needle \u5b57\u7b26\u4e32\uff0c\u5728 haystack \u5b57\u7b26\u4e32\u4e2d\u627e\u51fa needle \u5b57\u7b26\u4e32\u51fa\u73b0\u7684\u7b2c\u4e00\u4e2a\u4f4d\u7f6e (\u4ece0\u5f00\u59cb)\u3002\u5982\u679c\u4e0d\u5b58\u5728\uff0c\u5219\u8fd4\u56de&nbsp; <strong>-1<\/strong>\u3002<\/p>\n<p><strong>\u793a\u4f8b 1:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong> haystack = \"hello\", needle = \"ll\"\n\n<strong>\u8f93\u51fa:<\/strong> 2\n\n<\/pre>\n<p><strong>\u793a\u4f8b 2:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong> haystack = \"aaaaa\", needle = \"bba\"\n\n<strong>\u8f93\u51fa:<\/strong> -1\n\n<\/pre>\n<p><strong>\u8bf4\u660e:<\/strong><\/p>\n<p>\u5f53&nbsp;<code>needle<\/code>&nbsp;\u662f\u7a7a\u5b57\u7b26\u4e32\u65f6\uff0c\u6211\u4eec\u5e94\u5f53\u8fd4\u56de\u4ec0\u4e48\u503c\u5462\uff1f\u8fd9\u662f\u4e00\u4e2a\u5728\u9762\u8bd5\u4e2d\u5f88\u597d\u7684\u95ee\u9898\u3002<\/p>\n<p>\u5bf9\u4e8e\u672c\u9898\u800c\u8a00\uff0c\u5f53&nbsp;<code>needle<\/code>&nbsp;\u662f\u7a7a\u5b57\u7b26\u4e32\u65f6\u6211\u4eec\u5e94\u5f53\u8fd4\u56de 0 \u3002\u8fd9\u4e0eC\u8bed\u8a00\u7684&nbsp;<a href=\"https:\/\/baike.baidu.com\/item\/strstr\/811469\" target=\"_blank\" rel=\"noopener noreferrer\">strstr()<\/a>&nbsp;\u4ee5\u53ca Java\u7684&nbsp;<a href=\"https:\/\/docs.oracle.com\/javase\/7\/docs\/api\/java\/lang\/String.html#indexOf(java.lang.String)\" target=\"_blank\" rel=\"noopener noreferrer\">indexOf()<\/a>&nbsp;\u5b9a\u4e49\u76f8\u7b26\u3002<\/p>\n<p>**\u96be\u5ea6**: Easy<\/p>\n<p>**\u6807\u7b7e**: \u53cc\u6307\u9488\u3001 \u5b57\u7b26\u4e32\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\u6267\u884c\u7528\u65f6\uff1a40 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8680.24% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a13.5 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8697.09% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u4f7f\u7528\u53cc\u6307\u9488\u5206\u522b\u6307\u5411\u4e24\u5b57\u7b26\u4e32\n    \u5177\u4f53\u5b9e\u73b0\u89c1\u4ee3\u7801\u6ce8\u91ca\n\"\"\"\nclass Solution:\n    def strStr(self, haystack: str, needle: str) -&gt; int:\n        if needle == '':\n            return 0\n\n        len_i, len_j = len(haystack), len(needle)\n        record = -1         # \u521d\u59cb\u5316\u4e3a-1\uff0c \u7528\u4e8e\u8bb0\u5f55\u5b57\u7b26\u76f8\u7b49\u65f6\u7684\u4e0b\u6807\n        i, j = 0, 0         # \u53cc\u6307\u9488\n        while i &lt; len_i:    # \u5faa\u73af\u904d\u5386\u5b57\u7b26\u4e32haystack\n            if haystack[i] == needle[j]:    # \u82e5haystack\u5f53\u524d\u4e0b\u6807i\u6307\u5411\u7684\u5b57\u7b26\u4e0eneedle\u5b57\u7b26\u4e32\u5f53\u524d\u4e0b\u6807j\u6240\u6307\u5411\u7684\u5b57\u7b26\u76f8\u7b49\n                record = i  # record\u8bb0\u5f55\u5f53\u524di\u4e0b\u6807\n                j += 1      # \u540e\u79fbneedle\u5b57\u7b26\u4e32\u4e0b\u6807\n            else:\n                i = i-j     # \u5426\u5219\uff0c\u5c06i\u4e0b\u6807\u79fb\u52a8\u5230\u4e4b\u524d\u5f00\u59cb\u5339\u914d\u7684\u540e\u4e00\u9879\n                j = 0       # j\u6307\u9488\u6307\u5411needle\u7b2c\u4e00\u4e2a\u5b57\u7b26\n                record = -1 # record\u5f52-1\n            if j &gt; len_j-1: # \u5982needle\u5b57\u7b26\u4e32\u904d\u5386\u5b8c\u6bd5\uff0c\u5219\u8df3\u51fa\u5faa\u73af\n                break\n            else:\n                record = -1\n            i += 1\n        if record &gt; 0:  # \u5339\u914d\u6210\u529f\u65f6\uff0crecord\u6307\u5411\u5339\u914d\u5b57\u7b26\u4e32\u7684\u672b\u5c3e\uff0c\u9700\u8981\u79fb\u52a8\u5230\u5339\u914d\u5b57\u7b26\u4e32\u7684\u5f00\u59cb\n            record -= len_j-1\n        return record<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u5b9e\u73b0&nbsp;strStr()&nbsp;\u51fd\u6570\u3002 \u7ed9\u5b9a\u4e00\u4e2a&nbsp;haystack \u5b57\u7b26\u4e32\u548c\u4e00\u4e2a nee&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","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\/443"}],"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=443"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/443\/revisions"}],"predecessor-version":[{"id":444,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/443\/revisions\/444"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=443"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=443"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=443"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}