Complex Number Implementation

Here is my code for a program that adds and multiplies two complex numbers:

main.c

Code:

#include <stdio.h>
#include "complex.h"
 
int main ( int argc , char *argv[] ) {
 
  comp *ptr1, *ptr2, *j, *k, *sum, *product;
  double r, i;
 
  printf ( "Enter first complex number-\n" );
  printf ( "Enter real part: " );
  scanf  ( "%d",  &r );
  printf ( "Enter imaginary part: " );
  scanf  ( "%d",  &i );
 
  load_complex ( ptr1, r, i );
   
  printf ( "Enter second complex number-\n" );
  printf ( "Enter real part: " );
  scanf  ( "%d",  &r );
  printf ( "Enter imaginary part: " );
  scanf  ( "%d",  &i );
 
  load_complex ( ptr2, r, i );
 
  add_complex  ( sum, ptr1, ptr2 );
  retrieve_complex ( sum, j, k );
 
  printf ( "Sum is %lf%lf\n", sum->real, sum->imaginary );
   
  multiply_complex ( product, ptr1, ptr2 );
  retrieve_complex ( product, j, k );
 
  printf ( "Product is %lf%lf\n", product->real, product->imaginary );
 
  return ( 0 );
 
}

complex.h and complex.c:

Code:

/*
  complex.h
*/
 
typedef struct {
  double real;
  double imaginary;
} comp;
 
extern void load_complex ( comp *p_complex, double real,
					double imaginary );
 
extern void retrieve_complex ( comp *p_complex, double *p_real,
						double *imaginary );
 
extern void add_complex ( comp *p_sum, comp *p_complex1,
				   comp *p_complex2 );
 
extern void multiply_complex ( comp *p_product, comp *p_complex1,
						comp *p_complex2 );
}

/*
  complex.c
*/
 
#include "complex.h"
 
extern void load_complex ( comp *p_complex, double real, double imaginary ) {
 
  p_complex->real = real;
  p_complex->imaginary = imaginary;
 
}
 
extern void retrieve_complex ( comp *p_complex, double *p_real,
						double *p_imaginary ) {
 
  *p_real = p_complex->real;
  *p_imaginary = p_complex->imaginary;
 
}
 
extern void add_complex ( comp *p_sum, comp *p_complex1, comp *p_complex2 ) {
 
  p_sum->real = p_complex1->real + p_complex2->real;
 
  p_sum->imaginary = p_complex1->imaginary + p_complex2->imaginary;
 
}
 
extern void multiply_complex ( comp *p_product, comp *p_complex1,
						comp *p_complex2 ) {
 
  p_product->real = p_complex1->real * p_complex2->real -
	p_complex1->imaginary * p_complex2->imaginary;
 
  p_product->imaginary = p_complex1->real * p_complex2->imaginary *
	p_complex1->imaginary * p_complex2->real;
 
}

I'm receiving seg faults at the load_complex function ( gdb ), but I don't know what's wrong with the function. Originally, I was able to enter two complex numbers and then it seg faulted at retrieve, but for some reason now it's seg'n at the load's.. any ideas?

well, since a pointer is just a variable that contains an address - the object at that address has to exist for the pointer to be valid!

Code:

comp cmp1;
load_complex ( &cmp1, r, i );

Originally Posted by Sebastiani

well, since a pointer is just a variable that contains an address - the object at that address has to exist for the pointer to be valid!

d'oh.. thank you.

Cheers