#include <iostream>
#include <fstream>

using namespace std ;
#define MAXROWS 10
#define MAXCOLS 10

int main ()
{
    int i, j, k ;
    int n_rowsA, n_colsA;
    int n_rowsB, n_colsB;
    double A_ARRAY[MAXROWS][MAXCOLS];
    double B_ARRAY[MAXROWS][MAXCOLS];
    double zArray[MAXROWS][MAXCOLS];
    
    ifstream mat_in ;
    mat_in.open("matrix_compatibleAB.in");
    if ( mat_in.is_open())
        
        // mat_in >> i >>j >> k ;
    {
        mat_in >> n_rowsA >> n_colsA;
        cout << "The dimensions of A  are " << n_rowsA <<"\t and " << n_colsA << endl;
        
        for ( i =0; i< n_rowsA ; i++ )
        {
           // cout << "i = " << i;
            for ( j =0 ; j<n_colsA ;j++)
            {
               // cout << " \t  j = " << j ;
                mat_in >> A_ARRAY[i][j];
                cout <<  " A_ARRAY [ " << i << "][" << j << "] =" << A_ARRAY[i][j];
                
            }
            cout << endl;
       }
        mat_in >> n_rowsB >> n_colsB;
        cout << "The dimensions of B  are " << n_rowsB <<"\t and " << n_colsB << endl;
        
        for ( i =0; i< n_rowsB ; i++ )
        {
            // cout << "i = " << i;
            for ( j =0 ; j<n_colsB ;j++)
            {
                // cout << " \t  j = " << j ;
                mat_in >> B_ARRAY[i][j];
                cout <<  " B_ARRAY [ " << i << "][" << j << "] =" << B_ARRAY[i][j];
            }
            cout << endl;
        }
    }
    mat_in.close();
    
    if ( n_colsA != n_rowsB)
    {
        cout << " Invalid input. Please try again :" << endl;
        
    }
    else
    {
    
    
    for (i=0; i< n_rowsA; i++)
    {
        for( j=0 ; j< n_colsB; j++)
        {
            for( k =0 ; k< n_colsA; k++)
            {
                zArray[i][j] += A_ARRAY[i][k] * B_ARRAY[k][j];
                
            }
        }
    }
    
    for (i=0; i< n_rowsA; i++)
    {
        for (j=0; j <n_colsB; j++)
        {
            cout << " \t " << zArray[i][j];
        }
        cout << endl;
    }

    }
    
    return 0;
}