mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
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202 lines
22 KiB
JSON
202 lines
22 KiB
JSON
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"title": "Construct Binary Search Tree from Preorder Traversal",
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"content": "<p>Given an array of integers preorder, which represents the <strong>preorder traversal</strong> of a BST (i.e., <strong>binary search tree</strong>), construct the tree and return <em>its root</em>.</p>\n\n<p>It is <strong>guaranteed</strong> that there is always possible to find a binary search tree with the given requirements for the given test cases.</p>\n\n<p>A <strong>binary search tree</strong> is a binary tree where for every node, any descendant of <code>Node.left</code> has a value <strong>strictly less than</strong> <code>Node.val</code>, and any descendant of <code>Node.right</code> has a value <strong>strictly greater than</strong> <code>Node.val</code>.</p>\n\n<p>A <strong>preorder traversal</strong> of a binary tree displays the value of the node first, then traverses <code>Node.left</code>, then traverses <code>Node.right</code>.</p>\n\n<p> </p>\n<p><strong class=\"example\">Example 1:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2019/03/06/1266.png\" style=\"height: 386px; width: 590px;\" />\n<pre>\n<strong>Input:</strong> preorder = [8,5,1,7,10,12]\n<strong>Output:</strong> [8,5,10,1,7,null,12]\n</pre>\n\n<p><strong class=\"example\">Example 2:</strong></p>\n\n<pre>\n<strong>Input:</strong> preorder = [1,3]\n<strong>Output:</strong> [1,null,3]\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>1 <= preorder.length <= 100</code></li>\n\t<li><code>1 <= preorder[i] <= 1000</code></li>\n\t<li>All the values of <code>preorder</code> are <strong>unique</strong>.</li>\n</ul>\n",
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"difficulty": "Medium",
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"exampleTestcases": "[8,5,1,7,10,12]\n[1,3]",
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"categoryTitle": "Algorithms",
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"name": "Array",
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"name": "Binary Tree",
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"lang": "C++",
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"code": "/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode() : val(0), left(nullptr), right(nullptr) {}\n * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n * TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}\n * };\n */\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n \n }\n};",
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"code": "/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode() {}\n * TreeNode(int val) { this.val = val; }\n * TreeNode(int val, TreeNode left, TreeNode right) {\n * this.val = val;\n * this.left = left;\n * this.right = right;\n * }\n * }\n */\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n \n }\n}",
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"lang": "Python",
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"code": "# Definition for a binary tree node.\n# class TreeNode(object):\n# def __init__(self, val=0, left=None, right=None):\n# self.val = val\n# self.left = left\n# self.right = right\nclass Solution(object):\n def bstFromPreorder(self, preorder):\n \"\"\"\n :type preorder: List[int]\n :rtype: TreeNode\n \"\"\"\n ",
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"code": "# 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 bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:\n ",
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"code": "/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * struct TreeNode *left;\n * struct TreeNode *right;\n * };\n */\nstruct TreeNode* bstFromPreorder(int* preorder, int preorderSize) {\n \n}",
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"lang": "C#",
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"langSlug": "csharp",
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"code": "/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * public int val;\n * public TreeNode left;\n * public TreeNode right;\n * public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {\n * this.val = val;\n * this.left = left;\n * this.right = right;\n * }\n * }\n */\npublic class Solution {\n public TreeNode BstFromPreorder(int[] preorder) {\n \n }\n}",
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"lang": "JavaScript",
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"code": "/**\n * Definition for a binary tree node.\n * function TreeNode(val, left, right) {\n * this.val = (val===undefined ? 0 : val)\n * this.left = (left===undefined ? null : left)\n * this.right = (right===undefined ? null : right)\n * }\n */\n/**\n * @param {number[]} preorder\n * @return {TreeNode}\n */\nvar bstFromPreorder = function(preorder) {\n \n};",
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"lang": "TypeScript",
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"code": "/**\n * Definition for a binary tree node.\n * class TreeNode {\n * val: number\n * left: TreeNode | null\n * right: TreeNode | null\n * constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {\n * this.val = (val===undefined ? 0 : val)\n * this.left = (left===undefined ? null : left)\n * this.right = (right===undefined ? null : right)\n * }\n * }\n */\n\nfunction bstFromPreorder(preorder: number[]): TreeNode | null {\n \n};",
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"lang": "PHP",
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"code": "/**\n * Definition for a binary tree node.\n * class TreeNode {\n * public $val = null;\n * public $left = null;\n * public $right = null;\n * function __construct($val = 0, $left = null, $right = null) {\n * $this->val = $val;\n * $this->left = $left;\n * $this->right = $right;\n * }\n * }\n */\nclass Solution {\n\n /**\n * @param Integer[] $preorder\n * @return TreeNode\n */\n function bstFromPreorder($preorder) {\n \n }\n}",
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"code": "/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * public var val: Int\n * public var left: TreeNode?\n * public var right: TreeNode?\n * public init() { self.val = 0; self.left = nil; self.right = nil; }\n * public init(_ val: Int) { self.val = val; self.left = nil; self.right = nil; }\n * public init(_ val: Int, _ left: TreeNode?, _ right: TreeNode?) {\n * self.val = val\n * self.left = left\n * self.right = right\n * }\n * }\n */\nclass Solution {\n func bstFromPreorder(_ preorder: [Int]) -> TreeNode? {\n \n }\n}",
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"code": "/**\n * Example:\n * var ti = TreeNode(5)\n * var v = ti.`val`\n * Definition for a binary tree node.\n * class TreeNode(var `val`: Int) {\n * var left: TreeNode? = null\n * var right: TreeNode? = null\n * }\n */\nclass Solution {\n fun bstFromPreorder(preorder: IntArray): TreeNode? {\n \n }\n}",
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"code": "/**\n * Definition for a binary tree node.\n * class TreeNode {\n * int val;\n * TreeNode? left;\n * TreeNode? right;\n * TreeNode([this.val = 0, this.left, this.right]);\n * }\n */\nclass Solution {\n TreeNode? bstFromPreorder(List<int> preorder) {\n \n }\n}",
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"code": "/**\n * Definition for a binary tree node.\n * type TreeNode struct {\n * Val int\n * Left *TreeNode\n * Right *TreeNode\n * }\n */\nfunc bstFromPreorder(preorder []int) *TreeNode {\n \n}",
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"code": "# Definition for a binary tree node.\n# class TreeNode\n# attr_accessor :val, :left, :right\n# def initialize(val = 0, left = nil, right = nil)\n# @val = val\n# @left = left\n# @right = right\n# end\n# end\n# @param {Integer[]} preorder\n# @return {TreeNode}\ndef bst_from_preorder(preorder)\n \nend",
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"code": "/**\n * Definition for a binary tree node.\n * class TreeNode(_value: Int = 0, _left: TreeNode = null, _right: TreeNode = null) {\n * var value: Int = _value\n * var left: TreeNode = _left\n * var right: TreeNode = _right\n * }\n */\nobject Solution {\n def bstFromPreorder(preorder: Array[Int]): TreeNode = {\n \n }\n}",
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"code": "// Definition for a binary tree node.\n// #[derive(Debug, PartialEq, Eq)]\n// pub struct TreeNode {\n// pub val: i32,\n// pub left: Option<Rc<RefCell<TreeNode>>>,\n// pub right: Option<Rc<RefCell<TreeNode>>>,\n// }\n// \n// impl TreeNode {\n// #[inline]\n// pub fn new(val: i32) -> Self {\n// TreeNode {\n// val,\n// left: None,\n// right: None\n// }\n// }\n// }\nuse std::rc::Rc;\nuse std::cell::RefCell;\nimpl Solution {\n pub fn bst_from_preorder(preorder: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {\n \n }\n}",
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"code": "# Definition for a binary tree node.\n#\n# defmodule TreeNode do\n# @type t :: %__MODULE__{\n# val: integer,\n# left: TreeNode.t() | nil,\n# right: TreeNode.t() | nil\n# }\n# defstruct val: 0, left: nil, right: nil\n# end\n\ndefmodule Solution do\n @spec bst_from_preorder(preorder :: [integer]) :: TreeNode.t | nil\n def bst_from_preorder(preorder) do\n \n end\nend",
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"libraryUrl": null,
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"adminUrl": null,
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"challengeQuestion": null,
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"__typename": "QuestionNode"
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}
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}
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} |