创建一个名为Complex的类，进行复数的运算。Complex需要具有的功能：提供一个构造函数，它使这个类的对象在声明时得以初始化；

提供一个拷贝构造函数用来创建对象；

两个Complex的加法；实部相加，虚部相加；

两个Complex值相减：实部相减，虚部相减

两个Complex值相乘

以(a + b * i)的形式打印Complex的值，其中a为实部，b为虚部。-Create a class called Complex to carry out complex calculations. Complex need to do: provide a constructor, it makes the object of this class can be initialized in the declaration　to provide a copy constructor to create objects　the addition of two Complex　real sum, the imaginary part of the sum　 two Complex subtracted: subtract the real part, imaginary part of the subtraction of two Complex values ??multiplied by (a+ b* i) the value in the form of printed Complex, where a is real part, b is the imaginary part.