这一节主要学习Threading模块的一些基本操作,如获取线程数,添加线程等。...获取已激活的线程数 threading.active_count() 查看所有线程信息 threading.enumerate() 查看现在正在运行的线程 threading.current_thread() 添加线程
Symmetric Tree Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its...For example, this binary tree [1,2,2,3,4,4,3] is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But...思路: 题目意思是判断一棵树是不是对称的,可以用迭代或者递归来做 代码: go: /** * Definition for a binary tree node.
}else{ parent.rightChild = null; } // 引用类型,直接将它置为...null 就可以了 current = null; } // 2、左子树不为null,右子树为null else if(current.rightChild...else{ parent.rightChild = current.leftChild; } } // 3、左子树为null...tree = new Tree(); tree.insert(2); tree.insert(1); tree.insert(7); tree.insert...(5); tree.insert(4); tree.insert(6); tree.insert(10); tree.insert(8);
前言 如果是接触区块链开发相关的话题,Merkle Tree 是一个必需要了解的话题。 BTC和ETH都使用这项技术,但是数据结构不同。 应用侧重点也不同。...用意 Merkle tree 图片 注意这里的虚线,最后的叶子节点是真正挂数据的节点。...Merkle Patricia Tree TODO 以太坊 Merkle Patricia Tree 应用 参考链接 https://en.wikipedia.org/wiki/Merkle_tree
Same Tree Given two binary trees, write a function to check if they are the same or not....代码: go: /** * Definition for a binary tree node.
都是可以安装使用这个tree命令的。使用方式大同小异。这个很好用的tree命令,可以用于查看文件夹结构。本文中简单介绍tree命令的基本使用方式。...1、安装tree 如果centos系统里面不存在tree命令,是不会提示unknown command的,而是提示下面的信息: [root@docker-01 ~]# tree -bash: tree:...安装完成后,目录路径为: [root@docker-01 ~]# which tree /usr/bin/tree 2、查看当前目录结构 在tree命令后,增加目录路径即可。...列出当前目录,深度为1,如下: [root@docker-01 /]# tree ./ -L 1 ./ ├── bin -> usr/bin ├── boot ├── dev ├── etc ├── home...├── lib -> usr/lib ├── lib64 -> usr/lib64 ├── media 列出当前目录,深度为2,如下: [root@docker-01 /]# tree ./ -L 2
Tree generally....Decision Tree Builder Ideally for a perfect tree, the tree leaf should have only 1 class for classification...Decision Tree Stopping and pruning Now we know how to build the tree from top to the bottom, there is...Take regression tree as an example: We define \(T \subset T_0\) as a sub tree, which reaches an optimal...The higher it is, the smaller tree we will get.
Tree 描述 Little Valentine liked playing with binary trees very much....For the tree drawn above the preorder traversal is DBACEGF and the inorder traversal is ABCDEFG. ...She thought that such a pair of strings would give enough information to reconstruct the tree later (...two strings preord and inord, representing the preorder traversal and inorder traversal of a binary tree...Input is terminated by end of file.输出For each test case, recover Valentine's binary tree and print one
Binary Tree Paths Given a binary tree, return all root-to-leaf paths....代码: go: /** * Definition for a binary tree node.
B树的搜索,从根结点开始,如果查询的关键字与结点的关键字相等,那么就命中;否则,如果查询关键字比结点关键字小,就进入左儿子;如果比结点关键字大,就进入右儿子;如果左儿子或右儿子的指针为空,则报告找不到相应的关键字...B-树的搜索,从根结点开始,对结点内的关键字(有序)序列进行二分查找,如果命中则结束,否则进入查询关键字所属范围的儿子结点;重复,直到所对应的儿子指针为空,或已经是叶子结点; B-树的特性: ...其中,M为设定的非叶子结点最多子树个数,N为关键字总数; 所以B-树的性能总是等价于二分查找(与M值无关),也就没有B树平衡的问题; 由于M/2的限制,在插入结点时,如果结点已满,需要将结点分裂为两个各占...B*树定义了非叶子结点关键字个数至少为(2/3)*M,即块的最低使用率为2/3(代替B+树的1/2); B+树的分裂:当一个结点满时,分配一个新的结点,并将原结点中1/2的数据复制到新结点...,所有关键字都在叶子结点中出现,非叶子结点作为叶子结点的索引;B+树总是到叶子结点才命中; B*树:在B+树基础上,为非叶子结点也增加链表指针,将结点的最低利用率从1/2提高到2/3;
Invert Binary Tree Invert a binary tree....\ 7 2 / \ / \ 9 6 3 1 思路: 递归求解翻转每个不为nil的节点 代码: go: /** * Definition for a binary tree
Balanced Binary Tree Given a binary tree, determine if it is height-balanced....For this problem, a height-balanced binary tree is defined as: a binary tree in which the depth of the...Example 1: Given the following tree [3,9,20,null,null,15,7]: 3 / \ 9 20 / \ 15 7...而平衡二叉树的定义是一个二叉树_每个节点 _的左右两个子树的高度差的绝对值不超过1,所以,递归的思想,判断一个树是否为平衡二叉树,就看左右子树的高度差和左右子树是否为平衡二叉树。...代码: go: /** * Definition for a binary tree node.
把一棵二叉树变为链表(扁平化),也就是一棵所有节点要么没有子节点,要么只有右节点的二叉树。
Serialize and Deserialize Binary Tree Serialization is the process of converting a data structure or...Design an algorithm to serialize and deserialize a binary tree....to the original tree structure....**Example: ** You may serialize the following tree: 1 / \ 2 3 / \ 4 5 as "[1,2,3...,null,null,4,5]" Clarification: The above format is the same as how LeetCode serializes a binary tree
题目 Given the root of a binary search tree with distinct values, modify it so that every node has a new...value equal to the sum of the values of the original tree that are greater than or equal to node.val...As a reminder, a binary search tree is a tree that satisfies these constraints: The left subtree of a...The given tree is a binary search tree. 分析 题意:从右到左、下到上累加和,赋给当前节点。...观察后可知,遍历顺序为“右、根、左”,因此,以这个为一个“单元”,设计递归算法即可。
Minimum Depth of Binary Tree Given a binary tree, find its minimum depth....Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its...代码: go: /** * Definition for a binary tree node.
Binary Tree Postorder Traversal Given a binary tree, return the postorder traversal of its nodes' values...代码: go: /** * Definition for a binary tree node.
是一种多路搜索树: 1.定义任意非叶子结点最多只有M个儿子;且M>2; 2.根结点的儿子数为[2, M]; 3.除根结点以外的非叶子结点的儿子数为[M/2, M]; 4.每个结点存放至少M/2-1(取上整
Binary Search Tree Iterator Implement an iterator over a binary search tree (BST)....代码: go: /** * Definition for a binary tree node.
Maximum Depth of Binary Tree Given a binary tree, find its maximum depth....Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its...思路: 一棵空树的深度为零,也就是可以看做叶子节点的孩子节点的深度为零,叶子节点的深度为1,而一个树的深度和高度相同,所以求一个树的深度其实就是左右子树的深度的最大值加一。递归求解就可以。...代码: go: /** * Definition for a binary tree node.
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