/* complex.c */
#include <stdio.h> 
#include <complex.h>
        
int main(void)
{
    double x,y;
    double complex z,w;

    printf("real part?");
    scanf("%lf",&x);
    printf("imaginary part?");
    scanf("%lf",&y);

    z=x+y*I; /*  I*I == -1 */
    w=z*z;

    printf("      z = %f, %+fi\n", creal(z), cimag(z));
    printf("carg(z) = %f\n", carg(z));
    printf("cabs(z) = %f\n", cabs(z));
     printf("  z*z = %f, %+fi\n", creal(w), cimag(w));

    return 0;                       
}