题目:Unique Binary Search TreesII 如果要列出所有可能的二叉搜索树,可以在上面的思路上进一步. f(n) = f(0)*f(n-1) + f(1)*f(n-2) + ... + f(n-1)*f(0); 只要求出不同变量下的子树的所有情况,在整合到一起就可以了. 具体思路: 1.外循环遍历树根可能数值k(m->n); 2.分别求左右子树,左子树的可能取值范围(m->k-1),右子树的可能取值范围(k+1->n): 注意左右子树可能为空,此时后面合并的时候要分开…

LeetCode:Unique Binary Search Trees 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 分析:依次把每个节点作…

Unique Binary Search Trees 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 Unique Binary Search…

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 这道题实际上是Catalan Number卡塔兰数的一个例子,如果对卡塔兰数不熟悉的童鞋可能真…

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…

Unique Binary Search Trees II 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 \      …

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. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 思路: 仍和Unique Bin…

原题地址:https://oj.leetcode.com/problems/unique-binary-search-trees/ 题意: 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…

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 Tree Dynamic Programming     如果集合为空,只有一种BST,即空树…

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 题目的的意思是给出n个节点,求出有多少不同的二叉树,实际是计算卡特兰数可以参考二叉树.卡特兰数…

[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. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 [题意] 给定一个数字n, 问用1,2,3,4,5...n这n个值,能构造多少棵合…

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 题意:给定数n,二叉树的结点的值分别为1,2....n.问能组成多少种不同的二叉搜索树. 二叉…

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 [解题思路] 该题一直没有思路,到网上搜索了之后,得到如下结果 1              …

Question Given an integer 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…

Question 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 Solution 动态规划,将大问题划分为小问题,从底向上依次求解. 当规…

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 解题思路: 设有n个结点的二叉查找树有b[n]个,则设想对一个排好序的list,我们从第一个元…

原题地址:https://oj.leetcode.com/problems/unique-binary-search-trees-ii/ 题意:接上一题,这题要求返回的是所有符合条件的二叉查找树,而上一题要求的是符合条件的二叉查找树的棵数,我们上一题提过,求个数一般思路是动态规划,而枚举的话,我们就考虑dfs了.dfs(start, end)函数返回以start,start+1,...,end为根的二叉查找树. 代码: # Definition for a binary tree node #…

题意: 一棵BST有n个节点,每个节点的key刚好为1-n.问此树有多少种不同形态? 思路: 提示是动态规划. 考虑一颗有n个节点的BST和有n-1个节点的BST.从n-1到n只是增加了一个点n,那么点n可以放的地方并不多,而且有一些规律.由于n是最大的,所以必定是在最右边,但是它的上面和下面也可以有一些点,假设点n的上面有k个点,下面则为n-k-1个.观察到点n的上面的点必定是[1, n-k-1],下面的点是[n-k, n-1],而点数<n的BST的形态数都已经求出,那么枚举这个k值就行了.…

[Leetcode] Unique binary search trees 唯一二叉搜索树 Unique Binary Search Trees leetcode java 描述 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…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)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. (二)解题…

Given an integer n, generate all structurally unique BST's (binary search trees) that store values 1 ... n. 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 output corresponds to th…

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…

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,…

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…

Given n, how many structurally unique BST's (binary search trees) that store values 1 ... n? Example: Input: 3 Output: 5 Explanation: 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 这道题实际上是 卡塔兰数 Cat…

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, 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,…