Product of Two Matrices

#include <stdio.h>
#include <cstdlib>
#define A(I,J) (*(a+(I)*n+(J)))
#define B(I,J) (*(b+(I)*p+(J)))
#define C(I,J) (*(c+(I)*p+(J)))
// p is the number of column of B and C matrixes.
void functake(double *a,int m,int n);
void mat(double *a,double *b,double *c,int m,int n,int p);
//m number of rows in A , n number of column in A and number of rows in B , p number of column in B




int main(){

int row,col,i,j,row1,col1;
printf("row number");
scanf("%d",&row);
printf("\ncol number");
scanf("%d",&col);
printf("row number ");
scanf("%d",&row1);
printf("\ncol number");
scanf("%d",&col1);
if(col==row1){
double a[row][col];
double b[row1][col1];
double c[row][col1]={0,0};


/////////////// Taking Arrays
printf("\nElements of Array1\n");
for(i=0;i<row;i++)
for(j=0;j<col;j++)
scanf("%lf",&a[i][j]);

printf("Elements of Array2\n");
for(i=0;i<row1;i++)
for(j=0;j<col1;j++)
scanf("%lf",&b[i][j]);

////////////////////////////////
system("cls");
printf("Array1:\n");
for(i=0;i<row;i++)
{
for(j=0;j<col;j++)
printf("%.3lf",a[i][j]);

printf("\n");
}
printf("\nArray2;\n");
for(i=0;i<row1;i++){
for(j=0;j<col1;j++)
printf("%.3lf",b[i][j]);
printf("\n");

}


mat(&a[0][0],&b[0][0],&c[0][0],row,col,col1);






}else{
printf("You should study Lineer Algebra");
}




return 0;
}



void mat(double *a,double *b,double *c,int m,int n,int p){
double sum;
int i,j,k;


for(i=0;i<m;i++){
for(j=0;j<p;j++){
sum=0.0;
for(k=0;k<n;k++){
sum+=A(i,k)*B(k,j);
}

C(i,j)=sum;
}
}

printf("RESULT:\n");
for(i=0;i<m;i++){
for(j=0;j<p;j++)
printf("%.3lf",C(i,j));

printf("\n");

}



}