HelloWorld.cpp:

Code:

```
#include "stdafx.h"
#include <iostream>
#include <string>
#include "matrix.h"
using namespace std;
typedef unsigned char byte;
int main(int argc, _TCHAR* argv[])
{
matrix tst1(5,5);
matrix tst2(5,5);
matrix tst3(3,6);
tst1(3,4)=56;
tst3=tst2+tst1;
int tst=tst3(3,4);
cout << tst;
return 0;
};
```

Code:

```
// stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//
#pragma once
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers
#include <stdio.h>
#include <tchar.h>
// TODO: reference additional headers your program requires here
```

Code:

```
#define MATRIX_TYPE unsigned char
using namespace std;
//typedef unsigned char byte; --no longer needed due to #define directive
class matrix
{
MATRIX_TYPE* data_; //using underscores to distinguish internal variables -- worth changing the rest of the code?
int rows_,cols_;
public:
matrix(int rows, int cols); //constructor
~matrix(); //destructor DUMMY
MATRIX_TYPE& operator() (int row, int col); //subscript operator
MATRIX_TYPE operator() (int row, int col) const; // subscript operator for constants
matrix operator+(matrix op1); //matrix addition
matrix& operator=(const matrix& op1); //assignment of a matrix, to account for size differences
};
matrix::matrix(int rowin, int colin)
{
if(rowin==0){rows_=1;}else{rows_=rowin;};
if(colin==0){cols_=1;}else{cols_=rowin;};
data_=new MATRIX_TYPE[(rows_*cols_)-1];
};
matrix::~matrix()
{
delete[] data_;
};
MATRIX_TYPE& matrix::operator() (int row, int col)
{
if(row<rows_ && col<cols_)
{
return data_[(cols_*row)+col];
}else{
cout << "index out of range for this array" << endl;
return data_[0];
};
};
MATRIX_TYPE matrix::operator() (int row, int col) const
{
if(row<rows_ && col<cols_)
{
return data_[(cols_*row)+col];
}else{
cout << "index out of range for this array" << endl;
return data_[0];
};
};
matrix& matrix::operator=(const matrix& op1)
{
if(this != &op1) //must not be the same object!
{
delete[] data_; //get rid of the old data
rows_=op1.rows_; // make this new matrix have the same dimensions as the old one
cols_=op1.cols_;
data_=new MATRIX_TYPE[(rows_*cols_)-1]; //reassign space for data
for(int r=0;r<rows_;r++)
{
for(int c=0;c<cols_;c++)
{
data_[(cols_*r)+c]=op1(r,c); //copy data over from other matrix
};
};
};
return *this;
};
matrix matrix::operator +(matrix op1)
{
if((op1.rows_==rows_)&&(op1.cols_==cols_))
{
matrix result(rows_,cols_);
for(int r=0;r<rows_;r++)
{
for(int c=0;c<cols_;c++)
{
result(r,c)=op1(r,c)+data_[(cols_*r)+c]; // fill result matrix with sums
};
};
return result; // this line keeps causing a heap corruption!
}else{
cout << "matricies are not of equal dimension" << endl;
matrix ret(1,1);
return ret;
};
};
```