c++中的复数

参考来源：http://c.biancheng.net/view/703.html
１．　复数模板为 complex，include就可以用了，具体可以使用
complex<float>, complex<double>, complex<longdouble>
２．　加减乘除和普通的浮点数一样使用，包括 +=, -=, *=, /=。也可以判别两个复数是否相等。
３．　模方，辐角主值，共轭：norm(z), arg(z), conj(z)
参考代码如下

#include<iostream>
using namespace std;

#include<complex>
#include<cmath>

int main(){

        complex<double> z1, z2;
        cout<<" Please in put a complex number \n\t";
        cin>>z1;// e.g. (3,4) means 3+4i
        cout<<" Please in put another complex number \n\t";
        cin>>z2;
        cout<<"complex number z1 = "<<z1<<endl;
        cout<<" Re(z1) = "<<z1.real()<<endl;
        cout<<" Im(z1) = "<<z1.imag()<<endl;
        cout<<" z1 + z2 = "<<z1+z2<<endl;
        cout<<" z1 - z2 = "<< z1-z2 <<endl;
        cout<<" z1 * z2 = "<< z1*z2 <<endl;
        cout<<" z1 / z2 = "<< z1/z2 <<endl;
        if( z1 == z2 )cout<<" z1 == z2 "<<endl;
        cout<<" norm of z1 = "<< norm(z1) <<endl;
        cout<<" arg of z1 = "<< arg(z1) <<endl;
        cout<<" conjugate of z1 = "<< conj(z1) <<endl;
        cout<<" exp(z1) = "<<exp(z1)<<endl;

        return 0;
}

运行结果为

 Please in put a complex number 
	(3,4)
 Please in put another complex number 
	(4,5)
complex number z1 = (3,4)
 Re(z1) = 3
 Im(z1) = 4
 z1 + z2 = (7,9)
 z1 - z2 = (-1,-1)
 z1 * z2 = (-8,31)
 z1 / z2 = (0.780488,0.0243902)
 norm of z1 = 25
 arg of z1 = 0.927295
 conjugate of z1 = (3,-4)
 exp(z1) = (-13.1288,-15.2008)

挺好用。
补充：c++11标准与如下语句不兼容：

complex<double> z = 1 + 2i;

编译器会说　2i　是神马？所以用复数的时候得去掉 -std=c++11　编译选项。