建立一个复数类imaginary，其私有数据成员x和y表示复数的实部和虚部，构造函数imaginary用于对复数的实部和虚部初始化，友员函数add,sub,mul和div分别用于进行复数的加、减、乘和除法运算，静态函数show用于显示运算结果。在主函数中，实例化两个复数，并输入一个运算符，按运算符选择相应的友员函数进行复数运算，然后输出运算结果。

-The establishment of a complex class imaginary, its private data members x and y represent complex real and imaginary parts, used for complex constructor imaginary real and imaginary parts of initialization, Friends of the member functions add, sub, mul and div respectively. used for complex addition, subtraction, multiplication and division, show a static function used to display calculation results. In the main function, examples of two complex numbers, and enter an operator, press operator to select the appropriate member of the Friends of the complex computing functions, then the output result of the operation.