Singleton is a most widely used design pattern. If a class has and only has one instance at every moment, we call this design as singleton. For example, for class Mouse (not a animal mouse), we should design it in singleton. You job is to implement a…
Singleton 3 大要素: 1.有private static的句柄(成员变量即field) 2. constructor 必须为private 3.有public static的getInstance方法 class Solution { private static Solution instance; private Solution(){ } /** * @return: The same instance of this class every time */ public st…
Java Singleton: Singleton pattern restricts the instantiation of a class and ensures that only one instance of the class exists in the java virtual machine. The singleton class must provide a global access point to get the instance of the class.Singl…
Given an integer array, heapify it into a min-heap array. For a heap array A, A[0] is the root of heap, and for each A[i], A[i * 2 + 1] is the left child of A[i] and A[i * 2 + 2] is the right child of A[i]. Example Given [3,2,1,4,5], return [1,2,3,4,…
