题目 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. 分析 此题与上题本质相同,LeetCode 95 Unique Binary Search Trees要求得到全部二叉查找树,打印其层序遍历序列. 而此题,只要求元素 [1,n] 能构成的二…

1. Unique Binary Search Trees 题目链接 题目要求: 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 题目分析参…

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. 解题思路: 二叉查找树,刚上来无从下手,但仔细想想就能发现规律:以i为根节点,i的左子树都是小于i的,共有numTrees(i-1)种情况,i的右子树都是大于i的,共有numTrees(n-i…

题目 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. confused what "{1,#,2,3}" means? > read more on how binary tr…

给出 n,问由 1...n 为节点组成的不同的二叉查找树有多少种?例如,给出 n = 3,则有 5 种不同形态的二叉查找树:   1         3     3      2      1    \       /     /      / \      \     3     2     1      1   3      2    /     /       \                 \   2     1         2                 3详见:https…

题目如下: Python代码: def numTrees(self, n): """ :type n: int :rtype: int """ num=[0]*(n+1) num[0]=num[1]=1 for i in range(2,n+1): for j in range(i): num[i] += num[j]*num[i-j-1] return num[n]…

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. 解题思路: 参考Java for LeetCode 096 Unique Binary Search Trees思路,本题很容易解决.注意,…

[LeetCode]95. Unique Binary Search Trees II 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/unique-binary-search-trees-ii/description/ 题目描述: Given an integer n, generate all s…

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 此题是卡塔兰数的一个应用.注意是BST而不是普通的Binary Tree,所以要满足左比根小,…