/* CH5PR3.C: Program to add two sparse matrices */
#include <stdio.h>
#include <conio.h>
#include <alloc.h>
#define MAX1 3
#define MAX2 3
#define MAXSIZE 9
#define BIGNUM 100
struct sparse
{
int *sp ;
int row ;
int *result ;
} ;
void initsparse ( struct sparse * ) ;
void create_array ( struct sparse * ) ;
int count ( struct sparse ) ;
void display ( struct sparse ) ;
void create_tuple ( struct sparse *, struct sparse ) ;
void display_tuple ( struct sparse ) ;
void addmat ( struct sparse *, struct sparse, struct sparse ) ;
void display_result ( struct sparse ) ;
void delsparse ( struct sparse * ) ;
void main( )
{
struct sparse s[5] ;
int i ;
clrscr( ) ;
for ( i = 0 ; i <= 4 ; i++ )
initsparse ( &s[i] ) ;
create_array ( &s[0] ) ;
create_tuple ( &s[1], s[0] ) ;
display_tuple ( s[1] ) ;
create_array ( &s[2] ) ;
create_tuple ( &s[3], s[2] ) ;
display_tuple ( s[3] ) ;
addmat ( &s[4], s[1], s[3] ) ;
printf ( "\nResult of addition of two matrices: " ) ;
display_result ( s[4] ) ;
for ( i = 0 ; i <= 4 ; i++ )
delsparse ( &s[i] ) ;
getch( ) ;
}
/* initialises structure elements */
void initsparse ( struct sparse *p )
{
p -> sp = NULL ;
p -> result = NULL ;
}
/* dynamically creates the matrix */
void create_array ( struct sparse *p )
{
int n, i ;
/* allocate memory */
p -> sp = ( int * ) malloc ( MAX1 * MAX2 * sizeof ( int ) ) ;
/* add elements to the array */
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 s )
{
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", * ( s.sp + i ) ) ;
}
}
/* counts the number of non-zero elements */
int count ( struct sparse s )
{
int cnt = 0, i ;
for ( i = 0 ; i < MAX1 * MAX2 ; i++ )
{
if ( * ( s.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 ;
/* get the total number of non-zero elements
and add 1 to store total no. of rows, cols, and non-zero values */
p -> row = count ( s ) + 1 ;
/* allocate memory */
p -> sp = ( int * ) malloc ( p -> row * 3 * sizeof ( int ) ) ;
/* store information about
total no. of rows, cols, and non-zero values */
* ( p -> sp + 0 ) = MAX1 ;
* ( p -> sp + 1 ) = MAX2 ;
* ( p -> sp + 2 ) = p -> row - 1 ;
l = 2 ;
/* scan the array and store info. about non-zero values
in the 3-tuple */
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 the matrix */
void display_tuple ( struct sparse s )
{
int i, j ;
/* traverses the entire matrix */
printf ( "\nElements in a 3-tuple: \n" ) ;
j = ( * ( s.sp + 2 ) * 3 ) + 3 ;
for ( i = 0 ; i < j ; i++ )
{
/* positions the cursor to the new line for every new row */
if ( i % 3 == 0 )
printf ( "\n" ) ;
printf ( "%d\t", * ( s.sp + i ) ) ;
}
printf ( "\n" ) ;
}
/* carries out addition of two matrices */
void addmat ( struct sparse *p, struct sparse s1, struct sparse s2 )
{
int i = 1, j = 1, k = 1 ;
int elem = 1 ;
int max, amax, bmax ;
int rowa, rowb, cola, colb, vala, valb ;
/* get the total number of non-zero values
from both the matrices */
amax = * ( s1.sp + 2 ) ;
bmax = * ( s2.sp + 2 ) ;
max = amax + bmax ;
/* allocate memory for result */
p -> result = ( int * ) malloc ( MAXSIZE * 3 * sizeof ( int ) ) ;
while ( elem <= max )
{
/* check if i < max. non-zero values
in first 3-tuple and get the values */
if ( i <= amax )
{
rowa = * ( s1.sp + i * 3 + 0 ) ;
cola = * ( s1.sp + i * 3 + 1 ) ;
vala = * ( s1.sp + i * 3 + 2 ) ;
}
else
rowa = cola = BIGNUM ;
/* check if j < max. non-zero values
in secon 3-tuple and get the values */
if ( j <= bmax )
{
rowb = * ( s2.sp + j * 3 + 0 ) ;
colb = * ( s2.sp + j * 3 + 1 ) ;
valb = * ( s2.sp + j * 3 + 2 ) ;
}
else
rowb = colb = BIGNUM ;
/* if row no. of both 3-tuple are same */
if ( rowa == rowb )
{
/* if col no. of both 3-tuple are same */
if ( cola == colb )
{
/* add tow non-zero values
store in result */
* ( p -> result + k * 3 + 0 ) = rowa ;
* ( p -> result + k * 3 + 1 ) = cola ;
* ( p -> result + k * 3 + 2 ) = vala + valb ;
i++ ;
j++ ;
max-- ;
}
/* if col no. of first 3-tuple is < col no. of
second 3-tuple, then add info. as it is
to result */
if ( cola < colb )
{
* ( p -> result + k * 3 + 0 ) = rowa ;
* ( p -> result + k * 3 + 1 ) = cola ;
* ( p -> result + k * 3 + 2 ) = vala ;
i++ ;
}
/* if col no. of first 3-tuple is > col no. of
second 3-tuple, then add info. as it is
to result */
if ( cola > colb )
{
* ( p -> result + k * 3 + 0 ) = rowb ;
* ( p -> result + k * 3 + 1 ) = colb ;
* ( p -> result + k * 3 + 2 ) = valb ;
j++ ;
}
k++ ;
}
/* if row no. of first 3-tuple is < row no. of
second 3-tuple, then add info. as it is
to result */
if ( rowa < rowb )
{
* ( p -> result + k * 3 + 0 ) = rowa ;
* ( p -> result + k * 3 + 1 ) = cola ;
* ( p -> result + k * 3 + 2 ) = vala ;
i++ ;
k++ ;
}
/* if row no. of first 3-tuple is > row no. of
second 3-tuple, then add info. as it is
to result */
if ( rowa > rowb )
{
* ( p -> result + k * 3 + 0 ) = rowb ;
* ( p -> result + k * 3 + 1 ) = colb ;
* ( p -> result + k * 3 + 2 ) = valb ;
j++ ;
k++ ;
}
elem++ ;
}
/* add info about the total no. of rows,
cols, and non-zero values that the resultant array
contains to the result */
* ( p -> result + 0 ) = MAX1 ;
* ( p -> result + 1 ) = MAX2 ;
* ( p -> result + 2 ) = max ;
}
/* displays the contents of the matrix */
void display_result ( struct sparse s )
{
int i ;
/* traverses the entire matrix */
for ( i = 0 ; i < ( * ( s.result + 0 + 2 ) + 1 ) * 3 ; i++ )
{
/* positions the cursor to the new line for every new row */
if ( i % 3 == 0 )
printf ( "\n" ) ;
printf ( "%d\t", * ( s.result + i ) ) ;
}
}
/* deallocates memory */
void delsparse ( struct sparse *p )
{
if ( p -> sp != NULL )
free ( p -> sp ) ;
if ( p -> result != NULL )
free ( p -> result ) ;
}