{"id":379,"date":"2020-09-26T10:34:35","date_gmt":"2020-09-26T02:34:35","guid":{"rendered":"http:\/\/39.96.58.60\/?p=379"},"modified":"2022-10-18T16:39:35","modified_gmt":"2022-10-18T08:39:35","slug":"leetcode-109-%e6%9c%89%e5%ba%8f%e9%93%be%e8%a1%a8%e8%bd%ac%e6%8d%a2%e4%ba%8c%e5%8f%89%e6%90%9c%e7%b4%a2%e6%a0%91","status":"publish","type":"post","link":"https:\/\/www.yatenglg.cn\/blog\/?p=379","title":{"rendered":"Leetcode 109. \u6709\u5e8f\u94fe\u8868\u8f6c\u6362\u4e8c\u53c9\u641c\u7d22\u6811"},"content":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u5355\u94fe\u8868\uff0c\u5176\u4e2d\u7684\u5143\u7d20\u6309\u5347\u5e8f\u6392\u5e8f\uff0c\u5c06\u5176\u8f6c\u6362\u4e3a\u9ad8\u5ea6\u5e73\u8861\u7684\u4e8c\u53c9\u641c\u7d22\u6811\u3002<\/p>\n<p>\u672c\u9898\u4e2d\uff0c\u4e00\u4e2a\u9ad8\u5ea6\u5e73\u8861\u4e8c\u53c9\u6811\u662f\u6307\u4e00\u4e2a\u4e8c\u53c9\u6811<em>\u6bcf\u4e2a\u8282\u70b9&nbsp;<\/em>\u7684\u5de6\u53f3\u4e24\u4e2a\u5b50\u6811\u7684\u9ad8\u5ea6\u5dee\u7684\u7edd\u5bf9\u503c\u4e0d\u8d85\u8fc7 1\u3002<\/p>\n<p><strong>\u793a\u4f8b:<\/strong><\/p>\n<pre>\u7ed9\u5b9a\u7684\u6709\u5e8f\u94fe\u8868\uff1a [-10, -3, 0, 5, 9],\n\n\n\n\u4e00\u4e2a\u53ef\u80fd\u7684\u7b54\u6848\u662f\uff1a[0, -3, 9, -10, null, 5], \u5b83\u53ef\u4ee5\u8868\u793a\u4e0b\u9762\u8fd9\u4e2a\u9ad8\u5ea6\u5e73\u8861\u4e8c\u53c9\u641c\u7d22\u6811\uff1a\n\n\n\n      0\n\n     \/ \\\n\n   -3   9\n\n   \/   \/\n\n -10  5\n\n<\/pre>\n<p>**\u96be\u5ea6**: Medium<\/p>\n<p>**\u6807\u7b7e**: \u6df1\u5ea6\u4f18\u5148\u641c\u7d22\u3001 \u94fe\u8868\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\uff1a152 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e865.29% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a17.3 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8659.61% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u53cc\u6307\u9488\u627e\u4e2d\u5fc3\uff0c\u7136\u540e\u751f\u6210\u6811\n    \u5177\u4f53\u5b9e\u73b0\u89c1\u4ee3\u7801\u6ce8\u91ca\n\"\"\"\n\n\n# Definition for singly-linked list.\n# class ListNode:\n#     def __init__(self, val=0, next=None):\n#         self.val = val\n#         self.next = next\n# Definition for a binary tree node.\n# class TreeNode:\n#     def __init__(self, val=0, left=None, right=None):\n#         self.val = val\n#         self.left = left\n#         self.right = right\nclass Solution:\n    def sortedListToBST(self, head: ListNode) -&gt; TreeNode:\n        if head == None:    # \u5982\u679c\u5f53\u524d\u94fe\u8868\u4e3a\u7a7a\uff0c\u8fd4\u56de\u7a7a\n            return None\n        if head.next == None:   # \u5982\u679c\u5f53\u524d\u94fe\u8868\u4e3a\u5355\u4e2a\u5143\u7d20\uff0c\u8fd4\u56de\u7ed3\u70b9\n            return TreeNode(head.val)\n\n        pre = ListNode(0)\n        pre.next = head\n        fast, slow = head, pre  # \u5feb\u6162\u6307\u9488\n        while True:\n            fast = fast.next.next   # \u5faa\u73af\u5b8c\u6210\u540e\uff0cslow\u6307\u5411\u4e2d\u70b9\u524d\u7684\u4e00\u4e2a\u5143\u7d20\n            slow = slow.next\n            if fast == None or fast.next == None:\n                break\n\n        node = slow.next    # \u4e2d\u95f4\u5143\u7d20\n        right_link = slow.next.next # \u53f3\u534a\u90e8\u5206\u94fe\u8868\n        slow.next = None    # \u622a\u65ad\u94fe\u8868\n        left_link = pre.next    # \u5de6\u534a\u90e8\u5206\u94fe\u8868\n        node = TreeNode(node.val)   # \u5f53\u524d\u6811\u6839\u7ed3\u70b9\n        node.left = self.sortedListToBST(left_link) # \u9012\u5f52\u5bfb\u627e\u5de6\u5b50\u6811\u4e2d\u95f4\u503c\n        node.right = self.sortedListToBST(right_link)   # \u5bfb\u627e\u53f3\u5b50\u6811\u4e2d\u95f4\u503c\n\n        return node\n\n\"\"\"\n\u6267\u884c\u7528\u65f6\uff1a148 ms, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e865.29% \u7684\u7528\u6237\n\u5185\u5b58\u6d88\u8017\uff1a19.9 MB, \u5728\u6240\u6709 Python3 \u63d0\u4ea4\u4e2d\u51fb\u8d25\u4e8622.42% \u7684\u7528\u6237\n\n\u89e3\u9898\u601d\u8def\uff1a\n    \u5148\u5c06\u94fe\u8868\u8f6c\u6362\u4e3apython\u5217\u8868\u518d\u8fdb\u884c\u64cd\u4f5c\u3002\n    \u6027\u80fd\u4e0e\u4e0a\u4f8b\u662f\u76f8\u540c\u7684\uff0c\u4f46\u662f\u5bf9python\u6765\u8bf4\u66f4\u597d\u7406\u89e3\u4e00\u4e9b\n\"\"\"\nclass Solution:\n    def sortedListToBST(self, head: ListNode) -&gt; TreeNode:\n        link_list = []\n        while head:\n            link_list.append(head.val)\n            head = head.next\n\n        def f(link_list):\n            n = len(link_list)\n            if n == 0:\n                return None\n            if n == 1:\n                return TreeNode(link_list[0])\n            m = n \/\/ 2\n            node = TreeNode(link_list[m])\n            node.left = f(link_list[:m])\n            node.right = f(link_list[m + 1:])\n            return node\n\n        return f(link_list)<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed9\u5b9a\u4e00\u4e2a\u5355\u94fe\u8868\uff0c\u5176\u4e2d\u7684\u5143\u7d20\u6309\u5347\u5e8f\u6392\u5e8f\uff0c\u5c06\u5176\u8f6c\u6362\u4e3a\u9ad8\u5ea6\u5e73\u8861\u7684\u4e8c\u53c9\u641c\u7d22\u6811\u3002 \u672c\u9898\u4e2d\uff0c\u4e00\u4e2a\u9ad8\u5ea6\u5e73\u8861\u4e8c\u53c9\u6811\u662f\u6307\u4e00\u4e2a\u4e8c\u53c9&#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":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/379"}],"collection":[{"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=379"}],"version-history":[{"count":1,"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/379\/revisions"}],"predecessor-version":[{"id":380,"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=\/wp\/v2\/posts\/379\/revisions\/380"}],"wp:attachment":[{"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=379"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=379"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yatenglg.cn\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=379"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}