Something new I learnt from it: what is Treap and a O(n) construction https://en.wikipedia.org/wiki/Cartesian_tree#Efficient_construction class Solution { public: /** @param A: Given an integer array with no duplicates. @return: The root of max tree.…

Description Given an integer array with no duplicates. A max tree building on this array is defined as follow: The root is the maximum number in the array The left subtree and right subtree are the max trees of the subarray divided by the root number…

Given a binary tree, find the maximum path sum from root. The path may end at any node in the tree and contain at least one node in it. 给一棵二叉树,找出从根节点出发的路径中,和最大的一条. 这条路径可以在任何二叉树中的节点结束,但是必须包含至少一个点(也就是根了). /** * Definition of TreeNode: * public class Tr…

The structure of Segment Tree is a binary tree which each node has two attributes startand end denote an segment / interval. start and end are both integers, they should be assigned in following rules: The root's start and end is given bybuild method…

Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. Example Given the below binary tree: 1 / \ 2 3 return 6. For this problem we need to think about the problem in this way. Now we want the largest sum…

For a Maximum Segment Tree, which each node has an extra value max to store the maximum value in this node's interval. Implement a modify function with three parameter root, index and value to change the node's value with [start, end] = [index, index…

For an integer array (index from 0 to n-1, where n is the size of this array), in the corresponding SegmentTree, each node stores an extra attribute max to denote the maximum number in the interval of the array (index from start to end). Design a que…

描述 给出一棵二叉树,返回其节点值的层次遍历(逐层从左往右访问) 样例 给一棵二叉树 {3,9,20,#,#,15,7} : 3 / \ 9 20 / \ 15 7 返回他的分层遍历结果: [ [3], [9,20], [15,7] ] 挑战 挑战1:只使用一个队列去实现它 挑战2:用BFS算法来做 代码 GitHub 的源代码,请访问下面的链接: https://github.com/cwiki-us/java-tutorial/blob/master/src/test/java/com/os…

The structure of Segment Tree is a binary tree which each node has two attributes start and end denote an segment / interval. start and end are both integers, they should be assigned in following rules: The root's start and end is given by build meth…

Given a binary tree, return all root-to-leaf paths.Example Given the following binary tree: 1 /   \2     3 \  5 All root-to-leaf paths are: [  "1->2->5",  "1->3"] LeetCode上的原题,请参见我之前的博客Binary Tree Paths. 解法一: class Solution {…