prog.8.13.c

#include <stdio.h>

int main (void)
{
	void	scalarMultiply (int matrix[3][5], int scalar);
	void	displayMatrix (int matrix[3][5]);
	int		sampleMatrix[3][5] =
			{
				{  7, 16, 55, 13, 12 },
				{ 12, 10, 52,  0,  7 },
				{ -2,  1,  2,  4,  9 }
			};

	printf ("Original matrix:\n");
	displayMatrix (sampleMatrix);

	scalarMultiply (sampleMatrix, 2);

	printf ("\nMultiplied by 2:\n");
	displayMatrix (sampleMatrix);

	scalarMultiply (sampleMatrix, -1);

	printf ("\nThen multiplied by -1:\n");
	displayMatrix (sampleMatrix);

	return 0;
}

// Function to multiply a 3 x 5 array by a scalar

void scalarMultiply (int matrix[3][5], int scalar)
{
	int row, column;

	for ( row = 0; row < 3; ++row )
		for ( column = 0; column < 5; ++column )
			matrix[row][column] *= scalar;
}

void displayMatrix (int matrix[3][5])
{
	int row, column;

	for ( row = 0; row < 3; ++row ) {
		for ( column = 0; column < 5; ++column )
			printf ("%5i", matrix[row][column]);
		printf ("\n");
	}
}