Untitled
Java实现并发的几种方法Java程序默认以单线程方式运行。
synchronizedJava 用过synchronized 关键字来保证一次只有一个线程在执行代码块。
123public synchronized void code() { // TODO}
Volati
...
Untitled
Posted on
单例设计模式1Ensure a class has only one instance, and provide a global point of access to it.
单例设计模式是指某个类在整个系统中只能有一个实例对象可以被获取和使用的代码模式。
单例设计模式要求某个类只能有一个实例，并
...
用python读写HDF5格式文件
Posted on
|
In
Python
用python读写HDF5格式文件HDF5介绍 HDF(Hierarchical Data File)是美国国家高级计算应用中心(National Center for Supercomputing Application,NCSA)为了满足各种领
...
用Python来实现Base64编码和解码
Posted on
|
In
Python
用Python来实现Base64编码和解码 Base64是一种常见的编码和解码方式，Base64用7 bits的可打印字符来表示8-bit的二进制数据。base64在HTTP和XML上用的特别多，许多HTTP传输和email中都用到了Base64进
...
CMU Advanced DB 课程笔记#2：数据库工作负载和数据库事务模型
@TOC
CMU Advanced DB 课程笔记#2：数据库工作负载和数据库事务模型数据库工作负载：数据库工作负载有主要分为两种： 在线事务处理（OLTP）:每次只读取或更新数据库的一小部分，比如说用户去淘宝购物，用户只能对自己的购物车或者地址进
...
LeetCode 198. House Robber 打家劫舍
Posted on
|
In
LeetCode
198. House Robber题目描述You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only c
...
LeetCode 112. Path Sum 路径总和
Posted on
|
In
LeetCode
112. Path Sum 路径总和题目描述Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path e
...
LeetCode 139. Word Break 单词拆分
Posted on
|
In
LeetCode
139. Word Break 单词拆分题目描述Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented int
...
LeetCode 303. Range Sum Query - Immutable
Posted on
|
In
LeetCode
303. Range Sum Query - Immutable题目描述Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.
示例:Given num
...
LeetCode 726. Number of Atoms 原子的数量
Posted on
|
In
LeetCode
726. Number of Atoms 原子的数量题目描述Given a chemical formula (given as a string), return the count of each atom.
An atomic element always starts with an upp
...