#include <stdio.h>
#include <conio.h>
#include <alloc.h>
#define MAX1 3
#define MAX2 3
struct sparse
{
int *sp ;
int row ;
} ;
void initsparse ( struct sparse * ) ;
void create_array ( struct sparse * ) ;
void display ( struct sparse ) ;
int count ( struct sparse ) ;
void create_tuple ( struct sparse *, struct sparse ) ;
void display_tuple ( struct sparse ) ;
void delsparse ( struct sparse * ) ;
void main( )
{
struct sparse s1, s2 ;
int c ;
clrscr( );
initsparse ( &s1 ) ;
initsparse ( &s2 ) ;
create_array ( &s1 ) ;
printf ( "\nElements in Sparse Matrix: " ) ;
display ( s1 ) ;
c = count ( s1 ) ;
printf ( "\n\nNumber of non-zero elements: %d", c ) ;
create_tuple ( &s2, s1 ) ;
printf ( "\n\nArray of non-zero elements: " ) ;
display_tuple ( s2 ) ;
delsparse ( &s1 ) ;
delsparse ( &s2 ) ;
getch( ) ;
}
/* initialises element of structure */
void initsparse ( struct sparse *p )
{
p -> sp = NULL ;
}
/* dynamically creates the matrix of size MAX1 x MAX2 */
void create_array ( struct sparse *p )
{
int n, i ;
p -> sp = ( int * ) malloc ( MAX1 * MAX2 * sizeof ( int ) ) ;
for ( i = 0 ; i < MAX1 * MAX2 ; i++ )
{
printf ( "Enter element no. %d: ", i ) ;
scanf ( "%d", &n ) ;
* ( p -> sp + i ) = n ;
}
}
/* displays the contents of the matrix */
void display ( struct sparse p )
{
int i ;
/* traverses the entire matrix */
for ( i = 0 ; i < MAX1 * MAX2 ; i++ )
{
/* positions the cursor to the new line for every new row */
if ( i % MAX2 == 0 )
printf ( "\n" ) ;
printf ( "%d\t", * ( p.sp + i ) ) ;
}
}
/* counts the number of non-zero elements */
int count ( struct sparse p )
{
int cnt = 0, i ;
for ( i = 0 ; i < MAX1 * MAX2 ; i++ )
{
if ( * ( p.sp + i ) != 0 )
cnt++ ;
}
return cnt ;
}
/* creates an array that stores information about non-zero elements */
void create_tuple ( struct sparse *p, struct sparse s )
{
int r = 0 , c = -1, l = -1, i ;
p -> row = count ( s ) + 1 ;
p -> sp = ( int * ) malloc ( p -> row * 3 * sizeof ( int ) ) ;
* ( p -> sp + 0 ) = MAX1 ;
* ( p -> sp + 1 ) = MAX2 ;
* ( p -> sp + 2 ) = p -> row - 1 ;
l = 2 ;
for ( i = 0 ; i < MAX1 * MAX2 ; i++ )
{
c++ ;
/* sets the row and column values */
if ( ( ( i % MAX2 ) == 0 ) && ( i != 0 ) )
{
r++ ;
c = 0 ;
}
/* checks for non-zero element row, column and non-zero element value is assigned to the matrix */
if ( * ( s.sp + i ) != 0 )
{
l++ ;
* ( p -> sp + l ) = r ;
l++ ;
* ( p -> sp + l ) = c ;
l++ ;
* ( p -> sp + l ) = * ( s.sp + i ) ;
}
}
}
/* displays the contents of 3-tuple */
void display_tuple ( struct sparse p )
{
int i ;
for ( i = 0 ; i < p.row * 3 ; i++ )
{
if ( i % 3 == 0 )
printf ( "\n" ) ;
printf ( "%d\t", * ( p.sp + i ) ) ;
}
}
/* deallocates memory */
void delsparse ( struct sparse *p )
{ free ( p -> sp ) ;
}