{"id":483,"date":"2020-09-26T10:47:16","date_gmt":"2020-09-26T02:47:16","guid":{"rendered":"http:\/\/39.96.58.60\/?p=483"},"modified":"2022-10-18T16:39:04","modified_gmt":"2022-10-18T08:39:04","slug":"leetcode-784-%e5%ad%97%e6%af%8d%e5%a4%a7%e5%b0%8f%e5%86%99%e5%85%a8%e6%8e%92%e5%88%97","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=483","title":{"rendered":"Leetcode 784. \u5b57\u6bcd\u5927\u5c0f\u5199\u5168\u6392\u5217"},"content":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u5b57\u7b26\u4e32<code>S<\/code>\uff0c\u901a\u8fc7\u5c06\u5b57\u7b26\u4e32<code>S<\/code>\u4e2d\u7684\u6bcf\u4e2a\u5b57\u6bcd\u8f6c\u53d8\u5927\u5c0f\u5199\uff0c\u6211\u4eec\u53ef\u4ee5\u83b7\u5f97\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\u3002\u8fd4\u56de\u6240\u6709\u53ef\u80fd\u5f97\u5230\u7684\u5b57\u7b26\u4e32\u96c6\u5408\u3002<\/p>\n<p>&nbsp;<\/p>\n<pre><strong>\u793a\u4f8b\uff1a<\/strong>\n\n<strong>\u8f93\u5165\uff1a<\/strong>S = \"a1b2\"\n\n<strong>\u8f93\u51fa\uff1a<\/strong>[\"a1b2\", \"a1B2\", \"A1b2\", \"A1B2\"]\n\n\n\n<strong>\u8f93\u5165\uff1a<\/strong>S = \"3z4\"\n\n<strong>\u8f93\u51fa\uff1a<\/strong>[\"3z4\", \"3Z4\"]\n\n\n\n<strong>\u8f93\u5165\uff1a<\/strong>S = \"12345\"\n\n<strong>\u8f93\u51fa\uff1a<\/strong>[\"12345\"]\n\n<\/pre>\n<p>&nbsp;<\/p>\n<p><strong>\u63d0\u793a\uff1a<\/strong><\/p>\n<ul>\n<li><code>S<\/code>&nbsp;\u7684\u957f\u5ea6\u4e0d\u8d85\u8fc7<code>12<\/code>\u3002<\/li>\n<li><code>S<\/code>&nbsp;\u4ec5\u7531\u6570\u5b57\u548c\u5b57\u6bcd\u7ec4\u6210\u3002<\/li>\n<\/ul>\n<p>**\u96be\u5ea6**: Medium<\/p>\n<p>**\u6807\u7b7e**: \u4f4d\u8fd0\u7b97\u3001 \u56de\u6eaf\u7b97\u6cd5\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\uff1a52 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8693.23% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a14.9 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8652.35% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u56de\u6eaf\n    \u904d\u5386\u5b57\u7b26\u4e32\uff0c\u5982\u679c\u662f\u5b57\u6bcd\uff0c\u5219\u6539\u5199\u5176\u5927\u5c0f\u5199\uff0c\u5e76\u5c06\u6539\u5199\u524d\u548c\u6539\u5199\u540e\u7684\u6574\u6761\u5b57\u7b26\u4e32\u5747\u6dfb\u52a0\u5230\u6700\u540e\u7ed3\u679c\u4e2d\n    \u5177\u4f53\u5b9e\u73b0\u89c1\u4ee3\u7801\u6ce8\u91ca\n\"\"\"\nclass Solution:\n    def letterCasePermutation(self, S: str) -&gt; List[str]:\n        n = len(S)\n        result = []\n        def backtrack(begin, S):    # \u6307\u5b9a\u4e00\u4e2a\u8d77\u59cb\uff0c\u4e0e\u5f53\u524d\u5b57\u7b26\u4e32S\n            result.append(S[:])     # \u56e0\u4e3a\u662f\u6240\u6709\u7684\u6ee1\u8db3\u6761\u4ef6\u7684\u5b57\u7b26\u4e32\uff0c\u6240\u4ee5\u53ef\u4ee5\u76f4\u63a5\u6dfb\u52a0\u5230\u6700\u7ec8\u7ed3\u679c\n            if begin == n:  # \u8d85\u51fa\u5b57\u7b26\u4e32\u957f\u5ea6\u5219\u8df3\u51fa\n                return\n            for i in range(begin, n):   # \u4ece\u6307\u5b9a\u7684\u8d77\u59cb\u4f4d\u7f6e\u5f00\u59cb\uff0c\u67e5\u770b\u5f53\u524d\u5b57\u7b26\u4e32\n                if S[i].isalpha():\n                    if 'a' &lt;= S[i] &lt;= 'z':  # \u5982\u679c\u662f\u5c0f\u5199\uff0c\u5219\u6539\u6210\u5927\u5199\n                        backtrack(i+1, S[:i]+S[i].upper()+S[i+1:])\n                    elif 'A' &lt;= S[i] &lt;= 'Z':    # \u662f\u5927\u5199\uff0c\u5219\u6539\u6210\u5c0f\u5199\n                        backtrack(i+1, S[:i]+S[i].lower()+S[i+1:])\n\n        backtrack(0, S)\n        return result<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u5b57\u7b26\u4e32S\uff0c\u901a\u8fc7\u5c06\u5b57\u7b26\u4e32S\u4e2d\u7684\u6bcf\u4e2a\u5b57\u6bcd\u8f6c\u53d8\u5927\u5c0f\u5199\uff0c\u6211\u4eec\u53ef\u4ee5\u83b7\u5f97\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\u3002\u8fd4\u56de\u6240\u6709\u53ef\u80fd\u5f97\u5230\u7684\u5b57\u7b26\u4e32\u96c6&#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\/483"}],"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=483"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/483\/revisions"}],"predecessor-version":[{"id":484,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/483\/revisions\/484"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=483"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=483"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=483"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}