{"id":719,"date":"2020-09-26T11:14:13","date_gmt":"2020-09-26T03:14:13","guid":{"rendered":"http:\/\/39.96.58.60\/?p=719"},"modified":"2022-10-18T16:38:15","modified_gmt":"2022-10-18T08:38:15","slug":"leetcode-lcp-19-%e7%a7%8b%e5%8f%b6%e6%94%b6%e8%97%8f%e9%9b%86","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=719","title":{"rendered":"Leetcode LCP 19. \u79cb\u53f6\u6536\u85cf\u96c6"},"content":{"rendered":"

\u5c0f\u6263\u51fa\u53bb\u79cb\u6e38\uff0c\u9014\u4e2d\u6536\u96c6\u4e86\u4e00\u4e9b\u7ea2\u53f6\u548c\u9ec4\u53f6\uff0c\u4ed6\u5229\u7528\u8fd9\u4e9b\u53f6\u5b50\u521d\u6b65\u6574\u7406\u4e86\u4e00\u4efd\u79cb\u53f6\u6536\u85cf\u96c6 `leaves`\uff0c \u5b57\u7b26\u4e32 `leaves` \u4ec5\u5305\u542b\u5c0f\u5199\u5b57\u7b26 `r` \u548c `y`\uff0c \u5176\u4e2d\u5b57\u7b26 `r` \u8868\u793a\u4e00\u7247\u7ea2\u53f6\uff0c\u5b57\u7b26 `y` \u8868\u793a\u4e00\u7247\u9ec4\u53f6\u3002
\n\u51fa\u4e8e\u7f8e\u89c2\u6574\u9f50\u7684\u8003\u8651\uff0c\u5c0f\u6263\u60f3\u8981\u5c06\u6536\u85cf\u96c6\u4e2d\u6811\u53f6\u7684\u6392\u5217\u8c03\u6574\u6210\u300c\u7ea2\u3001\u9ec4\u3001\u7ea2\u300d\u4e09\u90e8\u5206\u3002\u6bcf\u90e8\u5206\u6811\u53f6\u6570\u91cf\u53ef\u4ee5\u4e0d\u76f8\u7b49\uff0c\u4f46\u5747\u9700\u5927\u4e8e\u7b49\u4e8e 1\u3002\u6bcf\u6b21\u8c03\u6574\u64cd\u4f5c\uff0c\u5c0f\u6263\u53ef\u4ee5\u5c06\u4e00\u7247\u7ea2\u53f6\u66ff\u6362\u6210\u9ec4\u53f6\u6216\u8005\u5c06\u4e00\u7247\u9ec4\u53f6\u66ff\u6362\u6210\u7ea2\u53f6\u3002\u8bf7\u95ee\u5c0f\u6263\u6700\u5c11\u9700\u8981\u591a\u5c11\u6b21\u8c03\u6574\u64cd\u4f5c\u624d\u80fd\u5c06\u79cb\u53f6\u6536\u85cf\u96c6\u8c03\u6574\u5b8c\u6bd5\u3002<\/p>\n

**\u793a\u4f8b 1\uff1a**<\/p>\n

>\u8f93\u5165\uff1a`leaves = “rrryyyrryyyrr”`<\/p>\n

><\/p>\n

>\u8f93\u51fa\uff1a`2`<\/p>\n

><\/p>\n

>\u89e3\u91ca\uff1a\u8c03\u6574\u4e24\u6b21\uff0c\u5c06\u4e2d\u95f4\u7684\u4e24\u7247\u7ea2\u53f6\u66ff\u6362\u6210\u9ec4\u53f6\uff0c\u5f97\u5230 “rrryyyyyyyyrr”<\/p>\n

**\u793a\u4f8b 2\uff1a**<\/p>\n

>\u8f93\u5165\uff1a`leaves = “ryr”`<\/p>\n

><\/p>\n

>\u8f93\u51fa\uff1a`0`<\/p>\n

><\/p>\n

>\u89e3\u91ca\uff1a\u5df2\u7b26\u5408\u8981\u6c42\uff0c\u4e0d\u9700\u8981\u989d\u5916\u64cd\u4f5c<\/p>\n

**\u63d0\u793a\uff1a**<\/p>\n

– `3 <= leaves.length <= 10^5`<\/p>\n

– `leaves` \u4e2d\u53ea\u5305\u542b\u5b57\u7b26 `’r’` \u548c\u5b57\u7b26 `’y’`<\/p>\n

**\u96be\u5ea6**: Medium<\/p>\n

**\u6807\u7b7e**:<\/p>\n

\n
\n# -*- coding: utf-8 -*-\n# @Author  : LG\n\n\"\"\"\n\u6267\u884c\u7528\u65f6\uff1a3020 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e865.04% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a33 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8632.54% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u52a8\u6001\u89c4\u5212\n    \u9898\u4e2d\u9700\u8981r*y*r*\u683c\u5f0f\uff0c\u7531r*\u3001r*y*\u3001r*y*r*\u4e00\u6b65\u4e00\u6b65\u6ee1\u8db3\n\n        r   r   r   y   y   y   r   r   y   y   y   r   r\n        0   0   0   1   2   3   3   3   4   5   6   6   6   # r*\n            1   1   0   0   0   1   2   2   2   2   3   4   # r*y*\n                1   2   1   1   0   0   1   2   3   2   2   # r*y*r*\n\n        y   r   y   y   r   y\n        1   1   2   3   3   4   # r*\n            2   1   1   2   2   # r*y*\n                3   2   1   2   # r*y*r*\n\n\"\"\"\nclass Solution:\n    def minimumOperations(self, leaves: str) -> int:\n        dp = [[ float('inf') for _ in range(3)]  for _ in leaves]\n        dp[0][0] = int(leaves[0]!='r')\n        for i in range(1, len(leaves)):\n            dp[i][0] = dp[i-1][0] + int(leaves[i]!='r')                     # r* \u53ea\u4f9d\u8d56\u4e8e r*\u60c5\u51b5\n            dp[i][1] = min(dp[i-1][0], dp[i-1][1]) + int(leaves[i]!='y')    # r*y* \u53ef\u7531 r*+y \u548cr*y*+y \u5f97\u5230\uff0c\u4f9d\u8d56\u4e8e r* \u548cr*y*\u60c5\u51b5\n            dp[i][2] = min(dp[i-1][1], dp[i-1][2]) + int(leaves[i]!='r')    # r*y*r* \u53ef\u7531 r*y*+r \u548c r*y*r*+r \u5f97\u5230\uff0c\u4f9d\u8d56\u4e8er*y* \u548c r*y*r*\u60c5\u51b5\n        return dp[-1][2]<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
\u5c0f\u6263\u51fa\u53bb\u79cb\u6e38\uff0c\u9014\u4e2d\u6536\u96c6\u4e86\u4e00\u4e9b\u7ea2\u53f6\u548c\u9ec4\u53f6\uff0c\u4ed6\u5229\u7528\u8fd9\u4e9b\u53f6\u5b50\u521d\u6b65\u6574\u7406\u4e86\u4e00\u4efd\u79cb\u53f6\u6536\u85cf\u96c6 `leaves`\uff0c \u5b57\u7b26\u4e32 `…<\/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\/719"}],"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=719"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/719\/revisions"}],"predecessor-version":[{"id":720,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/719\/revisions\/720"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=719"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=719"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=719"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}