{"id":419,"date":"2020-09-26T10:39:21","date_gmt":"2020-09-26T02:39:21","guid":{"rendered":"http:\/\/39.96.58.60\/?p=419"},"modified":"2022-10-18T16:39:23","modified_gmt":"2022-10-18T08:39:23","slug":"leetcode-501-%e4%ba%8c%e5%8f%89%e6%90%9c%e7%b4%a2%e6%a0%91%e4%b8%ad%e7%9a%84%e4%bc%97%e6%95%b0","status":"publish","type":"post","link":"http:\/\/www.yatenglg.cn\/blog\/?p=419","title":{"rendered":"Leetcode 501. \u4e8c\u53c9\u641c\u7d22\u6811\u4e2d\u7684\u4f17\u6570"},"content":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u6709\u76f8\u540c\u503c\u7684\u4e8c\u53c9\u641c\u7d22\u6811\uff08BST\uff09\uff0c\u627e\u51fa BST \u4e2d\u7684\u6240\u6709\u4f17\u6570\uff08\u51fa\u73b0\u9891\u7387\u6700\u9ad8\u7684\u5143\u7d20\uff09\u3002<\/p>\n<p>\u5047\u5b9a BST \u6709\u5982\u4e0b\u5b9a\u4e49\uff1a<\/p>\n<ul>\n<li>\u7ed3\u70b9\u5de6\u5b50\u6811\u4e2d\u6240\u542b\u7ed3\u70b9\u7684\u503c\u5c0f\u4e8e\u7b49\u4e8e\u5f53\u524d\u7ed3\u70b9\u7684\u503c<\/li>\n<li>\u7ed3\u70b9\u53f3\u5b50\u6811\u4e2d\u6240\u542b\u7ed3\u70b9\u7684\u503c\u5927\u4e8e\u7b49\u4e8e\u5f53\u524d\u7ed3\u70b9\u7684\u503c<\/li>\n<li>\u5de6\u5b50\u6811\u548c\u53f3\u5b50\u6811\u90fd\u662f\u4e8c\u53c9\u641c\u7d22\u6811<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff1a<\/p>\n<p>\u7ed9\u5b9a BST <code>[1,null,2,2]<\/code>,<\/p>\n<pre>   1\n\n    \\\n\n     2\n\n    \/\n\n   2\n\n<\/pre>\n<p><code>\u8fd4\u56de[2]<\/code>.<\/p>\n<p><strong>\u63d0\u793a<\/strong>\uff1a\u5982\u679c\u4f17\u6570\u8d85\u8fc71\u4e2a\uff0c\u4e0d\u9700\u8003\u8651\u8f93\u51fa\u987a\u5e8f<\/p>\n<p><strong>\u8fdb\u9636\uff1a<\/strong>\u4f60\u53ef\u4ee5\u4e0d\u4f7f\u7528\u989d\u5916\u7684\u7a7a\u95f4\u5417\uff1f\uff08\u5047\u8bbe\u7531\u9012\u5f52\u4ea7\u751f\u7684\u9690\u5f0f\u8c03\u7528\u6808\u7684\u5f00\u9500\u4e0d\u88ab\u8ba1\u7b97\u5728\u5185\uff09<\/p>\n<p>**\u96be\u5ea6**: Easy<\/p>\n<p>**\u6807\u7b7e**: \u6811\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\uff1a56 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8699.56% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a17.3 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8643.30% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u5177\u4f53\u5b9e\u73b0\u89c1\u4ee3\u7801\u6ce8\u91ca\n\"\"\"\n\n# Definition for a binary tree node.\n# class TreeNode:\n#     def __init__(self, x):\n#         self.val = x\n#         self.left = None\n#         self.right = None\n\nclass Solution:\n    def findMode(self, root: TreeNode) -&gt; List[int]:\n        if not root:\n            return []\n\n        record = {}         # \u7528\u4e8e\u4fdd\u5b58\u6bcf\u4e2a\u8282\u70b9\u51fa\u73b0\u7684\u6b21\u6570\n        def find(root):     # \u9012\u5f52\n            if root:\n                if root.val not in record:\n                    record[root.val] = 1\n                else:\n                    record[root.val] += 1\n                find(root.left)\n                find(root.right)\n\n        find(root)\n        result = {} # \u5404\u51fa\u73b0\u6b21\u6570\u7684\u8282\u70b9\n        for k, v in record.items():\n            if v not in result:\n                result[v] = [k]\n            else:\n                result[v].append(k)\n        return result[sorted(result.keys())[-1]]    # \u8fd4\u56de\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u8282\u70b9<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u6709\u76f8\u540c\u503c\u7684\u4e8c\u53c9\u641c\u7d22\u6811\uff08BST\uff09\uff0c\u627e\u51fa BST \u4e2d\u7684\u6240\u6709\u4f17\u6570\uff08\u51fa\u73b0\u9891\u7387\u6700\u9ad8\u7684\u5143\u7d20\uff09\u3002 \u5047\u5b9a BST \u6709\u5982&#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\/419"}],"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=419"}],"version-history":[{"count":1,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/419\/revisions"}],"predecessor-version":[{"id":420,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/419\/revisions\/420"}],"wp:attachment":[{"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=419"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=419"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=419"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}