题目 不同的二叉查找树 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? 样例 给出n = 3,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 解题 public class Solution { /** * @paramn n: An integer * @return: An integer */ public int numTrees(int n) { // write your code…

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 分析:这道题与unique binary…

iven a root of Binary Search Tree with unique value for each node. Remove the node with given value. If there is no such a node with given value in the binary search tree, do nothing. You should keep the tree still a binary search tree after removal.…

本文原题: LeetCode. 给定 n, 求解独特二叉搜寻树 (binary search trees) 的个数. 什么是二叉搜寻树? 二叉查找树(Binary Search Tree),或者是一棵空树,或者是具有下列性质的二叉树: 若它的左子树不空,则左子树上所有结点的值均小于它的根结点的值: 若它的右子树不空,则右子树上所有结点的值均大于它的根结点的值: 它的左.右子树也分别为二叉排序树. 举个栗子,给定 n = 3, 共有 5 个. 1 3 3 2 1 \ / / / \ \ 3 2 1…

题目: Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only nodes with…

本文为大便一箩筐的原创内容,转载请注明出处,谢谢:http://www.cnblogs.com/dbylk/p/4048209.html 原题: 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…

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:这道题的关键是找出规律,可以举几个例子帮助理解,化抽象为具体.实际上就是左子树书目*右子…

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 思路:dp.设数组res[i]表示n=i时的二叉搜索树个数. 先考虑最简单的情况,res[0]…

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…

由于BST的性质,所以右子树或者左子树中Node的值是连续的: 左子树 = [1, i -1], root = i, 右子树 = [i + 1, n].使用一个递归函数构造这个BST.其中返回值应该是所有的Unique BST的root node. def generateTrees(self, n): """ :type n: int :rtype: List[TreeNode] """ if n == 0: return [] return…