Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 confused what "{1,#,2…

Given an integer n, generate all structurally unique BST's (binary search trees) that store values 1 ... n. Example: Input: 3 Output: [   [1,null,3,2],   [3,2,null,1],   [3,1,null,null,2],   [2,1,3],   [1,null,2,null,3] ] Explanation: The above outpu…

Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 confused what"{1,#,2,…

Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 confused what "{1,#,2…

Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 一开始是想用递归解决,但看了标签是dp问题,就想了一下, 数目为k的bst,其每个 0 ~ k…

[096-Unique Binary Search Trees(唯一二叉搜索树)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given n, how many structurally unique BST's (binary search trees) that store values 1-n? For example, Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / /…

Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Calling next() will return the next smallest number in the BST Note: next() and hasNext() should run in average O(1) time and uses O…

http://oj.leetcode.com/problems/unique-binary-search-trees-ii/ 一题要求得出所有树的种类数,二题要求得出所有树. 在一题的基础上修改代码,还是要提前想清楚再写. #include <iostream> #include <vector> using namespace std; struct TreeNode { int val; TreeNode *left; TreeNode *right; TreeNode(int…

给定一个整数 n,求以 1 ... n 为节点组成的二叉搜索树有多少种? 示例: 输入: 3 输出: 5 解释: 给定 n = 3, 一共有 5 种不同结构的二叉搜索树: 假设n个节点存在二叉排序树的个数是G(n),1为根节点,2为根节点,...,n为根节点,当1为根节点时,其左子树节点个数为0,右子树节点个数为n-1,同理当2为根节点时,其左子树节点个数为1,右子树节点为n-2,所以可得G(n) = G(0)*G(n-1)+G(1)*(n-2)+...+G(n-1)*G(0) class So…

Unique Binary Search Trees II leetcode java [LeetCode]Unique Binary Search Trees II 异构二叉查找树II Unique Binary Search Trees II -- LeetCode 描述 Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Give…