/***********************

 * RowEchelon: Check if the matrix is row echelon or reduced row echelon format
 * @author: Kelsey Scheurich
 * @return: bool

 ********************/
void CGauss::RowEchelon( HWND _hDlg )
{
	// Create bool to store if row is allowed
	bool bAllowedZeroRow = true;

	/////////// Reduced Row Echelon //////////////
	// Create floats to store matrix variables
	float fA;
	float fB;
	float fC;
	float fD;

	// Loop through 3 rows
	for( int i = 2 ; i >= 0; i-- )
	{
		// For each item in the row
		for( int j = 0; j <= 4; ++j )
		{
			// Set as matrix value
			fA = m_fMatrix[ i ][ 0 ];
			fB = m_fMatrix[ i ][ 1 ];
			fC = m_fMatrix[ i ][ 2 ];
			fD = m_fMatrix[ i ][ 3 ];

			// If they are all 0
			if( ( fA == 0 ) && ( fB == 0 ) && ( fC == 0 ) && ( fD == 0 ) )
			{
				// Row is full of 0
				if( bAllowedZeroRow == false)
				{
					// row is not allowed
					return;
				}
			}
			else
			{
				// Row is not allowed
				bAllowedZeroRow = false;
			}
		}
	}

	// Create variables for current value, found, leading one index
	int iRowAboveLeadingOneIndex = ( -1 );
	float fCurrentValue;
	bool bFoundReduced = true;
	bool bAllowedNonZero;

	// For each row
	for( int i = 0; i < 3; i++ )
	{
		// Set to true
		bAllowedNonZero = true;
		// For each item in the row
		for( int j = 0; j < 3; ++j )
		{
			// Get current value
			fCurrentValue = m_fMatrix[ j ][ i ];

			// If it is 0, carry on
			if( fCurrentValue == 0 )
			{
				continue;
			}
			// Else if it is 1 and the one above is allowed to be non 0
			else if( ( fCurrentValue == 1 ) && ( i > iRowAboveLeadingOneIndex ) && bAllowedNonZero )
			{
				//Set to false and set to i
				iRowAboveLeadingOneIndex = i;
				bAllowedNonZero = false;
			}
			// Else is not echelon
			else
			{
				if( bAllowedNonZero )
				{
					bAllowedNonZero = false;
				}
				else
				{
					bFoundReduced = false;
					break;
				}

			}
		}
	}
	// If have found reduces and the one above is not -1
	if( bFoundReduced && iRowAboveLeadingOneIndex != ( -1 ) )
	{
		// Open message box
		MessageBox( _hDlg, L"You have reached Reduced Row Echelon", L"Reduced Row Echelon", MB_ICONINFORMATION | MB_OK );
		return;
	}
	///////////////// Row Echelon /////////////////
	// Set back to -1
	iRowAboveLeadingOneIndex = ( -1 );
	// Loop through matrix
	for( int i = 0; i < 3; i++ )
	{
		for( int j = 0; j < 3; j++ )
		{
			// Get matrix value
			fCurrentValue = m_fMatrix[ i ][ j ];

			// If it is 0, continue
			if( fCurrentValue == 0 )
			{
				continue;
			}
			// Else if its not 0
			else if( fCurrentValue != 0 )
			{
				// Check if i is 0 & j is smaller than row above
				if( i == 0 || j > iRowAboveLeadingOneIndex )
				{
					// Set to j
					iRowAboveLeadingOneIndex = j;
					break;
				}
				else
				{
					return;
				}
			}
			else
			{
				return;
			}
		}
	}
	// If row above is -1
	if( iRowAboveLeadingOneIndex != ( -1 ) )
	{
		// Reached row echelon
		MessageBox( _hDlg, L"You have reached Row Echelon", L"Row Echelon", MB_ICONINFORMATION | MB_OK );
	}

}