#include <iostream>
#include <cstdlib>
using namespace std;

// Global variables
const int MAX_ROWS = 50;
const int MAX_COLS = 50;

// Notice that function prototypes need not include the variable names.
void read_matrix( double [MAX_ROWS][MAX_COLS], int&, int& );
void prnt_matrix( double [MAX_ROWS][MAX_COLS], int, int, short );
void lin_comb( double [MAX_ROWS][MAX_COLS], double [MAX_ROWS][MAX_COLS],
               double [MAX_ROWS][MAX_COLS], double, double, int, int );

int main()
{
    double A[MAX_ROWS][MAX_COLS], B[MAX_ROWS][MAX_COLS], C[MAX_ROWS][MAX_COLS];
    int rowsA, colsA, rowsB, colsB;
    
    cout << "First matrix...\n"; 
    read_matrix( A, rowsA, colsA );
    cout << "\n";
    cout << "Second matrix...\n"; 
    read_matrix( B, rowsB, colsB );
    cout << "\n";
    if ( rowsA == rowsB && colsA == colsB ) {
        lin_comb( A, B, C, 2, -3, rowsA, colsA );
        prnt_matrix( C, rowsA, colsA, 8 );
    }
    else {
        cout << "Dimension mismatch - Addition not defined.\n";
    }
    
    cout << "\n\n"; system( "PAUSE" );
    return( EXIT_SUCCESS );
}
   
void read_matrix( double array[MAX_ROWS][MAX_COLS], int &rows, int &cols ) 
{
    cout << "Enter the number of rows and columns.\n"
         << "# of Rows = ";
    cin >> rows;
    cout << "# of Columns = ";
    cin >> cols;
    cout << endl;
    
    for ( int i = 0; i < rows; i++ ) {
        for ( int j = 0; j < cols; j++ ) {
            cout << "Entry [" << i << "][" << j << "] = ";
            cin >> array[i][j];
        }
    }
}

#include <iomanip>
void prnt_matrix( double array[MAX_ROWS][MAX_COLS], int rows, int cols, 
                  short prt_width )
{
    cout << setiosflags( ios::left );
    for ( int i = 0; i < rows; i++ ) {
        for ( int j = 0; j < cols; j++ ) {
            cout << setw( prt_width ) << array[i][j] << "  ";
        }
        cout << "\n";
    }
}

void lin_comb( double array1[MAX_ROWS][MAX_COLS], 
               double array2[MAX_ROWS][MAX_COLS],
               double array3[MAX_ROWS][MAX_COLS],
               double c1, double c2, int rows, int cols )
{
    for ( int i = 0; i < rows; i++ ) {
        for ( int j = 0; j < cols; j++ ) {
            array3[i][j] = c1 * array1[i][j] + c2 * array2[i][j];
        }
    }
}