不可变对象和类 由不可变类创建的对象就是不可变对象,要使一个类成为不可变的,它必须满足下面的需求: 所有数据域都是私有的 没有修改器方法 没有一个访问器的方法,它会返回一个指向可变数据域的引用 看下面的代码: public class Main { public static void main(String args[]) { Student student = new Student(11222333, "John"); java.util.Date dateCreatedDate
Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place. Follow up: Did you use extra space?A straight forward solution using O(mn) space is probably a bad idea.A simple improvement uses O(m + n) space, but still
Machine and statistical learning wizards are becoming more eager to perform analysis with Spark MLlibrary if this is only possible. It’s trendy, posh, spicy and gives the feeling of doing state of the art machine learning and being up to date with th