/* Partial implementation of type and operators for complex numbers. */
#include <stdio.h>
#include <math.h>
/* User-defined complex number type */
typedef struct {
double real, imag;
} complex_t;
/* complex number input function returns standard scanning error code
1 => valid scan, 0 => error, negative EOF value => end of file */
int
scan_complex (complex_t *c)
{
int status;
status = scanf("%lf%lf", &c->real, &c->imag);
if (status == 2)
status = 1;
else if (status != EOF)
status = 0;
return (status);
}
/* complex output function displays value as (a + bi) or (a - bi),
dropping a or b if they round to 0 unless both round to 0 */
void
print_complex (complex_t c)
{
double a, b;
char sign;
a = c.real;
b = c.imag;
printf("(");
if (fabs(a) < .005 && fabs(b) < .005) {
printf("%.2lf", 0.0);
} else if (fabs(b) < .005) {
printf("%.2lf", a);
} else if (fabs(a) < .005) {
printf("%.2lfi", b);
} else {
if (b < 0)
sign = '-';
else
sign = '+';
printf("%.2lf %c %.2lfi", a, sign, fabs(b));
}
printf(")");
}
/* returns the sum of complex values c1 and c2 */
complex_t
add_complex (complex_t c1, complex_t c2)
{
complex_t csum;
csum.real = c1.real + c2.real;
csum.imag = c1.imag + c2.imag;
return (csum);
}
/* returns the difference of complex values c1 and c2 */
complex_t
subtract_complex (complex_t c1, complex_t c2)
{
complex_t cdiff;
cdiff.real = c1.real - c2.real;
cdiff.imag = c1.imag - c2.imag;
return (cdiff);
}
/* returns the absolute value of complex number c */
complex_t
abs_complex (complex_t c)
{
complex_t cabs;
cabs.real = sqrt(c.real * c.real + c.imag * c.imag);
cabs.imag = 0;
return (cabs);
}
int
main (void)
{
complex_t com1, com2;
/* Gets the two complex numbers */
printf("Enter the real and imaginary parts of a complex number\n");
printf("separated by a space > ");
scan_complex(&com1);
printf("Enter a second complex number > ");
scan_complex(&com2);
/* forms and displays the sum */
printf("\n");
print_complex(com1);
printf(" + ");
print_complex(com2);
printf(" = ");
print_complex(add_complex(com1, com2));
/* forms and displays the difference */
printf("\n\n");
print_complex(com1);
printf(" - ");
print_complex(com2);
printf(" = ");
print_complex(subtract_complex(com1, com2));
/* forms and displays the absolute value of the first number */
printf("\n\n|");
print_complex(com1);
printf("| = ");
print_complex(abs_complex(com1));
printf("\n");
return (0);
}
