Thread: Matrix multiplication using 1-d arrays

I know how to properly multiply matrices, so that isn't the problem.

However, I'm working on a program that multiplies 2 dynamically created matrices, but the data is stored in one dimensional arrays. I thought it would be easier than creating an array of pointers that would point to arrays, but I can't figure out how to properly implement matrix multiplication on the 2 arrays.

In the followoing code, Matrix is a struct containing (int Row, int Col, and int *Data). Of course, this code doesn't multiply properly:

Code:

void matrixMultiply(int MatrixOne, int MatrixTwo)
{ 
    cout << "Multiplying..." << endl;
    int colCount = 0,
        rowInc = 0,
        colInc = 0,
        Mat1Size = mList[MatrixOne].Row * mList[MatrixOne].Col,
        Mat2Size = mList[MatrixTwo].Row * mList[MatrixTwo].Col;
    
    Matrix Answer; //creates answer matrix
    Answer.Row = mList[MatrixOne].Row;
    Answer.Col = mList[MatrixTwo].Col;
    Answer.Data = new int[Answer.Row*Answer.Col]; //allocates matrix space
    for (int ii = 0; ii < Answer.Row*Answer.Col; ii++)
    {
        Answer.Data[ii] = 0; //initializes all data content to zero
    }
    for (int Count = 0; Count < Answer.Row*Answer.Col; Count++)
    {
        colCount = 0;
        colInc = 0;
        for (int rowCount = rowInc; rowCount < mList[MatrixOne].Row + rowInc; rowCount++)
        { //adding and multiplying rows/cols
             if (rowCount > Mat1Size)
                 break;
             Answer.Data[Count] += (mList[MatrixOne].Data[rowCount] * mList[MatrixTwo].Data[colCount]);
             colCount += mList[MatrixTwo].Col;
             if (colCount > Mat2Size)
             {
                 colInc++;
                 colCount = colInc;
             }
        }
        rowInc += mList[MatrixOne].Row;
    }
    matrixOutput(Answer);
}

Any help would be greatly appreciated.