编写多个Java接口和类，实现一个简易的计算器，可以让用户选择计算类型（最大公约数和最小公倍数）之后，输入两个整数，计算器自动调用相应的算子类计算结果并输出显示。-Write multiple Java interfaces and classes that implement a simple calculator that allows the user to the type of calculation (the greatest common divisor and least co