摘要： 单例的五种实现 1. 立即加载：类加载 // 类加final防止子类覆盖方法 破坏单例性质 public final class Singleton1 implements Serializable { // 构造方法私有 但仍可以通过反射创建对象 private Singleton1() {} / 阅读全文

摘要： 归并排序 public static void mergeSort(int[] a) { mergeSort(a, 0, a.length - 1); } public static void mergeSort(int[] a, int start, int end) { // 递归出口：数组长度 阅读全文

摘要： Item1: consider static factory methods instead of constructors advantages: They have names They not required to create a new object each time they are 阅读全文

摘要： Goal: quantify the relationship between problem size and running time(time complexity) The total running time of a program is determined by two primar 阅读全文