问题 该问题的实际应用 Suppose that we are designing a program to translate text from English to French. For each occurrence of each English word in the text, we need to look up its French equivalent. We could perform these lookup operations by building a binar…

p400 页最后一段 When j >= i , we need to select a root kr from among ki ... kj and then make an optimal binary search tree with keys ki ... kr-1 as its left subtree and an optimal binary search tree with keys kr+1 ... kj as its right subtree.What happens…

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…

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 \          …

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  …

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…

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 \ / / / \ \ 3 2 1 1 3 2 / / \ \…

本题利用BST的特性来用DP求解.由于BST的性质,所以root左子树的node全部<root.而右子树的node全部>root. 左子树 = [1, j-1], root = j, 右子树 = [j+1, n] dp[n] = sum(dp[j - 1] * dp[n - j - 1]) def numTrees(self, n): """ :type n: int :rtype: int """ dp = [0]*(n+1) dp…

Given two Binary Search Trees, find common nodes in them. In other words, find intersection of two BSTs. Example: from: http://www.geeksforgeeks.org/print-common-nodes-in-two-binary-search-trees/ Method 1 (Simple Solution) A simple way is to one by o…