{"id":431,"date":"2020-09-26T10:40:52","date_gmt":"2020-09-26T02:40:52","guid":{"rendered":"http:\/\/39.96.58.60\/?p=431"},"modified":"2022-10-18T16:39:23","modified_gmt":"2022-10-18T08:39:23","slug":"leetcode-89-%e6%a0%bc%e9%9b%b7%e7%bc%96%e7%a0%81","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=431","title":{"rendered":"Leetcode 89. \u683c\u96f7\u7f16\u7801"},"content":{"rendered":"<p>\u683c\u96f7\u7f16\u7801\u662f\u4e00\u4e2a\u4e8c\u8fdb\u5236\u6570\u5b57\u7cfb\u7edf\uff0c\u5728\u8be5\u7cfb\u7edf\u4e2d\uff0c\u4e24\u4e2a\u8fde\u7eed\u7684\u6570\u503c\u4ec5\u6709\u4e00\u4e2a\u4f4d\u6570\u7684\u5dee\u5f02\u3002<\/p>\n<p>\u7ed9\u5b9a\u4e00\u4e2a\u4ee3\u8868\u7f16\u7801\u603b\u4f4d\u6570\u7684\u975e\u8d1f\u6574\u6570<em> n<\/em>\uff0c\u6253\u5370\u5176\u683c\u96f7\u7f16\u7801\u5e8f\u5217\u3002\u5373\u4f7f\u6709\u591a\u4e2a\u4e0d\u540c\u7b54\u6848\uff0c\u4f60\u4e5f\u53ea\u9700\u8981\u8fd4\u56de\u5176\u4e2d\u4e00\u79cd\u3002<\/p>\n<p>\u683c\u96f7\u7f16\u7801\u5e8f\u5217\u5fc5\u987b\u4ee5 0 \u5f00\u5934\u3002<\/p>\n<p>&nbsp;<\/p>\n<p><strong>\u793a\u4f8b 1:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong>&nbsp;2\n\n<strong>\u8f93\u51fa:<\/strong>&nbsp;<code>[0,1,3,2]<\/code>\n\n<strong>\u89e3\u91ca:<\/strong>\n\n00 - 0\n\n01 - 1\n\n11 - 3\n\n10 - 2\n\n\n\n\u5bf9\u4e8e\u7ed9\u5b9a\u7684&nbsp;<em>n<\/em>\uff0c\u5176\u683c\u96f7\u7f16\u7801\u5e8f\u5217\u5e76\u4e0d\u552f\u4e00\u3002\n\n\u4f8b\u5982\uff0c<code>[0,2,3,1]<\/code>&nbsp;\u4e5f\u662f\u4e00\u4e2a\u6709\u6548\u7684\u683c\u96f7\u7f16\u7801\u5e8f\u5217\u3002\n\n\n\n00 - 0\n\n10 - 2\n\n11 - 3\n\n01 - 1<\/pre>\n<p><strong>\u793a\u4f8b&nbsp;2:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong>&nbsp;0\n\n<strong>\u8f93\u51fa:<\/strong>&nbsp;<code>[0]\n\n<strong>\u89e3\u91ca:<\/strong> \u6211\u4eec\u5b9a\u4e49<\/code>\u683c\u96f7\u7f16\u7801\u5e8f\u5217\u5fc5\u987b\u4ee5 0 \u5f00\u5934\u3002<code>\n\n&nbsp;    \u7ed9\u5b9a<\/code>\u7f16\u7801\u603b\u4f4d\u6570\u4e3a<code> <em>n<\/em> \u7684\u683c\u96f7\u7f16\u7801\u5e8f\u5217\uff0c\u5176\u957f\u5ea6\u4e3a 2<sup>n<\/sup><\/code>\u3002<code>\u5f53 <em>n<\/em> = 0 \u65f6\uff0c\u957f\u5ea6\u4e3a 2<sup>0<\/sup> = 1\u3002\n\n&nbsp;    \u56e0\u6b64\uff0c\u5f53 <em>n<\/em> = 0 \u65f6\uff0c\u5176\u683c\u96f7\u7f16\u7801\u5e8f\u5217\u4e3a [0]\u3002<\/code>\n\n<\/pre>\n<p>**\u96be\u5ea6**: Medium<\/p>\n<p>**\u6807\u7b7e**: \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\uff1a180 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e865.52% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a16.2 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e865.06% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u56de\u6eaf\n    \u56de\u6eaf\uff0c\u76f4\u5230\u627e\u5230\u4e00\u4e2a\u6ee1\u8db3\u6761\u4ef6\u7684\u503c\n\"\"\"\nclass Solution:\n    def grayCode(self, n: int) -&gt; List[int]:\n        result = []\n        def backtrack(start:list, current:list):\n            if len(current) &gt;= 2**n:\n                for b in current:\n                    num = 0\n                    for i, v in enumerate(b[::-1]):\n                        num += v*2**i\n                    result.append(num)\n                return True\n\n            for i in range(n):\n                start_copy = start[:]\n                start_copy[i] = 0 if start_copy[i]==1 else 1\n                if start_copy not in current:\n                    current.append(start_copy)\n                    if backtrack(start_copy, current):\n                        return True\n                    current.pop()\n        if backtrack([0]*n,[[0]*n]):\n            return result\n        else:\n            return []\n\n\n\"\"\"\n\u6267\u884c\u7528\u65f6\uff1a52 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8616.03% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a13.7 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8647.18% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u4f8b\uff1a n = 4\n    \n            0   0   0   0   0000\n                        1   0001\n                    1   1   0011\n                        0   0010\n                1   1   0   0110\n                        1   0111\n                    0   1   0101\n                        0   0100\n            1   1   0   0   1100\n                        1   1101\n                    1   1   1111\n                        0   1110\n                0   1   0   1010\n                        1   1011\n                    0   1   1001\n                        0   1000\n\"\"\"\nclass Solution:\n    def grayCode(self, n: int) -&gt; List[int]:\n        strings = []\n        for i in range(n):\n            string=''\n            reverse = False\n            while len(string) &lt; (2**n):\n                if reverse:\n                    string += '1' * int(2 ** i) + '0' * int(2 ** i)\n                else:\n                    string += '0' * int(2 ** i) + '1' * int(2 ** i)\n                reverse = not reverse\n            strings.append(string)\n\n        result = [0 for _ in range(2**n)]\n        for j, string in enumerate(strings):\n            for i, s in enumerate(string):\n                result[i] += int(s) * (2 ** j)\n        return result\n<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u683c\u96f7\u7f16\u7801\u662f\u4e00\u4e2a\u4e8c\u8fdb\u5236\u6570\u5b57\u7cfb\u7edf\uff0c\u5728\u8be5\u7cfb\u7edf\u4e2d\uff0c\u4e24\u4e2a\u8fde\u7eed\u7684\u6570\u503c\u4ec5\u6709\u4e00\u4e2a\u4f4d\u6570\u7684\u5dee\u5f02\u3002 \u7ed9\u5b9a\u4e00\u4e2a\u4ee3\u8868\u7f16\u7801\u603b\u4f4d\u6570\u7684\u975e\u8d1f\u6574\u6570&#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\/431"}],"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=431"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/431\/revisions"}],"predecessor-version":[{"id":432,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/431\/revisions\/432"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=431"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=431"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}