{"id":325,"date":"2020-09-26T10:26:05","date_gmt":"2020-09-26T02:26:05","guid":{"rendered":"http:\/\/39.96.58.60\/?p=325"},"modified":"2022-10-18T16:39:50","modified_gmt":"2022-10-18T08:39:50","slug":"leetcode-309-%e6%9c%80%e4%bd%b3%e4%b9%b0%e5%8d%96%e8%82%a1%e7%a5%a8%e6%97%b6%e6%9c%ba%e5%90%ab%e5%86%b7%e5%86%bb%e6%9c%9f","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=325","title":{"rendered":"Leetcode 309. \u6700\u4f73\u4e70\u5356\u80a1\u7968\u65f6\u673a\u542b\u51b7\u51bb\u671f"},"content":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u6574\u6570\u6570\u7ec4\uff0c\u5176\u4e2d\u7b2c<em>&nbsp;i<\/em>&nbsp;\u4e2a\u5143\u7d20\u4ee3\u8868\u4e86\u7b2c&nbsp;<em>i<\/em>&nbsp;\u5929\u7684\u80a1\u7968\u4ef7\u683c \u3002\u200b<\/p>\n<p>\u8bbe\u8ba1\u4e00\u4e2a\u7b97\u6cd5\u8ba1\u7b97\u51fa\u6700\u5927\u5229\u6da6\u3002\u5728\u6ee1\u8db3\u4ee5\u4e0b\u7ea6\u675f\u6761\u4ef6\u4e0b\uff0c\u4f60\u53ef\u4ee5\u5c3d\u53ef\u80fd\u5730\u5b8c\u6210\u66f4\u591a\u7684\u4ea4\u6613\uff08\u591a\u6b21\u4e70\u5356\u4e00\u652f\u80a1\u7968\uff09:<\/p>\n<ul>\n<li>\u4f60\u4e0d\u80fd\u540c\u65f6\u53c2\u4e0e\u591a\u7b14\u4ea4\u6613\uff08\u4f60\u5fc5\u987b\u5728\u518d\u6b21\u8d2d\u4e70\u524d\u51fa\u552e\u6389\u4e4b\u524d\u7684\u80a1\u7968\uff09\u3002<\/li>\n<li>\u5356\u51fa\u80a1\u7968\u540e\uff0c\u4f60\u65e0\u6cd5\u5728\u7b2c\u4e8c\u5929\u4e70\u5165\u80a1\u7968 (\u5373\u51b7\u51bb\u671f\u4e3a 1 \u5929)\u3002<\/li>\n<\/ul>\n<p><strong>\u793a\u4f8b:<\/strong><\/p>\n<pre><strong>\u8f93\u5165:<\/strong> [1,2,3,0,2]\n\n<strong>\u8f93\u51fa: <\/strong>3 \n\n<strong>\u89e3\u91ca:<\/strong> \u5bf9\u5e94\u7684\u4ea4\u6613\u72b6\u6001\u4e3a: [\u4e70\u5165, \u5356\u51fa, \u51b7\u51bb\u671f, \u4e70\u5165, \u5356\u51fa]<\/pre>\n<p>**\u96be\u5ea6**: Medium<\/p>\n<p>**\u6807\u7b7e**: \u52a8\u6001\u89c4\u5212\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\u4e8676.60% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a14.3 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8610.86% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u52a8\u6001\u89c4\u5212\n    \u5728\u5904\u7406\u8be5\u95ee\u9898\u65f6\uff0c\u4e3b\u8981\u5b58\u5728\u4e09\u79cd\u72b6\u6001\uff0c\u4e70\uff0c \u5356\uff0c \u51b7\u51bb\u671f\u3002\u5fc5\u987b\u5728\u4e0d\u6301\u6709\u60c5\u51b5\u4e0b\u624d\u53ef\u4ee5\u4e70\u8fdb\uff0c\u5728\u6301\u6709\u72b6\u6001\u4e0b\u624d\u53ef\u4ee5\u5356\u51fa\u3002\n    \u5c06\u8be5\u95ee\u9898\u5206\u4e3a\u4ee5\u4e0b\u4e09\u79cd\u60c5\u51b5\uff1a\n        1. \u4e0d\u6301\u6709\u80a1\u7968\n            \u53ef\u4ee5\u4e3a\u524d\u4e00\u5929\u4e0d\u6301\u6709\uff0c\u6216\u524d\u4e00\u5929\u6301\u6709\u5356\u51fa\n        2. \u6301\u6709\u80a1\u7968\n            \u53ef\u4ee5\u4e3a\u524d\u4e00\u5929\u6301\u6709\uff0c\u6216\u524d\u4e00\u5929\u4e3a\u51b7\u51bb\u671f\uff0c\u4eca\u5929\u4e70\u5165\n        3. \u51b7\u51bb\u671f\n            \u51b7\u51bb\u671f\u4e3a\u65e9\u4e00\u5929\u521a\u51fa\u552e\u80a1\u7968\uff0c\u4eca\u5929\u4e0d\u80fd\u4e70\u5165\uff0c\u6b64\u65f6\u5229\u6da6\u4e0e\u524d\u4e00\u5929\u4e0d\u6301\u6709\u65f6\u76f8\u540c\u3002\n                * \u82e5\u65e9\u4e00\u5929\u4e0d\u6301\u6709\u662f\u7531\u518d\u524d\u4e00\u5929\u4e0d\u6301\u6709\u72b6\u6001\u800c\u6765\uff0c\u90a3\u4e48\u5229\u6da6\u4e0d\u4f1a\u6709\u53d8\u5316\uff0c\u6240\u4ee5\u53ef\u4ee5\u540c\u4e00\u903b\u8f91\u5904\u7406\u3002\n\n\"\"\"\nclass Solution:\n    def maxProfit(self, prices: List[int]) -&gt; int:\n        n = len(prices)\n        if n &lt; 2:\n            return 0\n        dp = [[0 for _ in range(3)] for _ in range(n)]\n        dp[0][1] = -prices[0]               # \u7b2c\u4e00\u5929\u6301\u6709\n        dp[1][0] = max(dp[0][0], dp[0][1]+prices[1])    # \u7b2c\u4e8c\u5929\u4e0d\u6301\u6709\uff1a(\u7b2c\u4e00\u5929\u4e0d\u6301\u6709\uff0c \u7b2c\u4e00\u5929\u6301\u6709\u5356\u51fa)\n        dp[1][1] = max(dp[0][1], dp[0][0]-prices[1])    # \u7b2c\u4e8c\u5929\u6301\u6709\uff1a(\u7b2c\u4e00\u5929\u6301\u6709\uff0c\u7b2c\u4e00\u5929\u4e0d\u6301\u6709\u4e70\u8fdb)\n        dp[1][2] = dp[0][0]                             # \u51b7\u5374\u671f\u5f53\u5929\uff0c\u5229\u6da6\u4e0e\u524d\u4e00\u5929\u4e0d\u6301\u6709\u80a1\u7968\u5229\u6da6\u4e00\u81f4\n        for i in range(2, n):\n            dp[i][0] = max(dp[i-1][0], dp[i-1][1] + prices[i])      # \u4e0d\u6301\u6709\u80a1\u7968\u7684\u60c5\u51b5\uff1a(\u539f\u672c\u4e0d\u6301\u6709\uff0c\u65e9\u4e00\u5929\u6301\u6709\u5356\u51fa)\n            dp[i][1] = max(dp[i-1][1], dp[i-1][2] - prices[i])      # \u6301\u6709\u80a1\u7968\u7684\u60c5\u51b5\uff1a(\u539f\u672c\u6301\u6709\uff0c\u539f\u672c\u4e0d\u6301\u6709\u4e70\u8fdb\uff0c\u9700\u8981\u6ce8\u610f\u7684\u662f\u4e70\u8fdb\u65f6\uff0c\u5fc5\u987b\u662f\u51b7\u51bb\u671f\u4e4b\u540e\u624d\u53ef\u4ee5)\n            dp[i][2] = dp[i-1][0]                                   # \u51b7\u51bb\u671f\u4e0e\u524d\u4e00\u5929\u4e0d\u6301\u6709\u65f6\u5229\u6da6\u4e00\u81f4\n        return max(dp[-1])\n<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u6574\u6570\u6570\u7ec4\uff0c\u5176\u4e2d\u7b2c&nbsp;i&nbsp;\u4e2a\u5143\u7d20\u4ee3\u8868\u4e86\u7b2c&nbsp;i&nbsp;\u5929\u7684\u80a1\u7968\u4ef7\u683c \u3002\u200b &#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\/325"}],"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=325"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/325\/revisions"}],"predecessor-version":[{"id":326,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/325\/revisions\/326"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=325"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=325"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=325"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}