Bcsl 033 data and file structures lab s2-2
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This program multiplies two sparse matrices in C. It takes in two matrices from the user and converts them to sparse form by removing all zero values and storing the row, column, and value of non-zero elements. It then performs the multiplication by iterating through each non-zero element in the first matrix and matching columns with row elements in the second matrix, summing the products of the values at matched indices into the result matrix. Finally, it prints out the sparse and result matrices.
![S2-2
Write a program in ‘C’ language to multiply two sparse matrices
#include<stdio.h>
#include<conio.h>
struct sp
{
int row,col;
int mat[10][10];
int sp[50][3];
};
/* to convert the entered matrix to sparce form,by eleminating zero values*/
int convsp(struct sp *M )
{
int e=1,i,j;
printf("enter number of rows and columns in the matrix");
scanf("%d%d",&M->row,&M->col);
printf("enter the matrix");
for(i=0;i<M->row;++i)
for(j=0;j<M->col;++j)
{
scanf("%d",&M->mat[i][j]);
if(M->mat[i][j]!=0)
{
M->sp[e][0]=i;
M->sp[e][1]=j;
M->sp[e][2]=M->mat[i][j];
e++;
}
}
M->sp[0][0]=M->row; //store number of rows to first(row,col) of sparse
M->sp[0][1]=M->col; //store number of cols to first row,second col
M->sp[0][2]=e-1; //store total number of non zero values to 3rd column
return M->sp[0][2]; //return total number of non zero elements
}
mult(struct sp M1,int e1, struct sp M2,int e2)
{
int sum[10][10],i,j,k1,k2;
for(i=0;i<10;++i)
for(j=0;j<10;++j)
sum[i][j]=0;
for(i=1;i<=e1;++i)
for(j=1;j<=e2;++j)
if(M1.sp[i][1]==M2.sp[j][0])
{
k1=M1.sp[i][0];
k2=M2.sp[j][1];
sum[k1][k2]+=M1.sp[i][2]*M2.sp[j][2];
}
printf("nproduct matrixn");
for(i=0;i<M1.row;++i)
{
for(j=0;j<M2.col;++j)
printf("%dt",sum[i][j]);
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![S2-2
printf("n");
}
}
void printsp(int n,struct sp matx)
{
int i,j;
for(i=0;i<=n;++i)
{
for(j=0;j<3;++j)
printf("%dt",matx.sp[i][j]);
printf("n");
}
}
main()
{
int ele1,ele2;
struct sp m1,m2;
clrscr();
ele1=convsp(&m1);
printf("n SPARSE MATRIX1n");
printsp(ele1,m1);
ele2=convsp(&m2);
printf("n SPARSE MATRIX2n");
printsp(ele2,m2);
if(m1.row!=m2.col)
printf("matrices are not compatible for multiplication");
else
mult(m1,ele1,m2,ele2);
getch();
}
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Bcsl 033 data and file structures lab s2-2
- 1. S2-2 Write a program in ‘C’ language to multiply two sparse matrices #include<stdio.h> #include<conio.h> struct sp { int row,col; int mat[10][10]; int sp[50][3]; }; /* to convert the entered matrix to sparce form,by eleminating zero values*/ int convsp(struct sp *M ) { int e=1,i,j; printf("enter number of rows and columns in the matrix"); scanf("%d%d",&M->row,&M->col); printf("enter the matrix"); for(i=0;i<M->row;++i) for(j=0;j<M->col;++j) { scanf("%d",&M->mat[i][j]); if(M->mat[i][j]!=0) { M->sp[e][0]=i; M->sp[e][1]=j; M->sp[e][2]=M->mat[i][j]; e++; } } M->sp[0][0]=M->row; //store number of rows to first(row,col) of sparse M->sp[0][1]=M->col; //store number of cols to first row,second col M->sp[0][2]=e-1; //store total number of non zero values to 3rd column return M->sp[0][2]; //return total number of non zero elements } mult(struct sp M1,int e1, struct sp M2,int e2) { int sum[10][10],i,j,k1,k2; for(i=0;i<10;++i) for(j=0;j<10;++j) sum[i][j]=0; for(i=1;i<=e1;++i) for(j=1;j<=e2;++j) if(M1.sp[i][1]==M2.sp[j][0]) { k1=M1.sp[i][0]; k2=M2.sp[j][1]; sum[k1][k2]+=M1.sp[i][2]*M2.sp[j][2]; } printf("nproduct matrixn"); for(i=0;i<M1.row;++i) { for(j=0;j<M2.col;++j) printf("%dt",sum[i][j]); Page 1
- 2. S2-2 printf("n"); } } void printsp(int n,struct sp matx) { int i,j; for(i=0;i<=n;++i) { for(j=0;j<3;++j) printf("%dt",matx.sp[i][j]); printf("n"); } } main() { int ele1,ele2; struct sp m1,m2; clrscr(); ele1=convsp(&m1); printf("n SPARSE MATRIX1n"); printsp(ele1,m1); ele2=convsp(&m2); printf("n SPARSE MATRIX2n"); printsp(ele2,m2); if(m1.row!=m2.col) printf("matrices are not compatible for multiplication"); else mult(m1,ele1,m2,ele2); getch(); } Page 2