/* c99: example regarding complex numbers */

#include <stdio.h>
#include <complex.h>
#include <tgmath.h>
 
int main(void)
{

  /* Square 1 */
  double complex z1 = I * I;
  printf("I * I = %.1f+%.1fi\n", creal(z1), cimag(z1));

  /* Square 2 */
  double complex z2 = pow(I, 2); // imaginary unit squared
  printf("pow(I, 2) = %.1f+%.1fi\n", creal(z2), cimag(z2));

  /* Conjugates numbers */
  double complex z4 = 1+2*I, z5 = 1-2*I; // conjugates
  printf("(1+2i)*(1-2i) = %.1f+%.1fi\n", creal(z4*z5), cimag(z4*z5));

  /* Square root */
  double complex z6=csqrt(-1);
  printf("sqrt(-1) = %.1f+%.1fi\n", creal(z6), cimag(z6));
      
}