EndSem

Questions

Question-1

// Preprocessor directives.
#include <stdio.h>

const int MAX_DIMENSIONS = 100; // 2D array size.

// Function prototypes.
void Replace( int row_dim, int col_dim, int matrix[MAX_DIMENSIONS][MAX_DIMENSIONS] );

int main() // Start main.
{ // Start.

	// Variable initialisations.
	int mat[MAX_DIMENSIONS][MAX_DIMENSIONS];
	int M, N;

	int mat_non_boundary[MAX_DIMENSIONS][MAX_DIMENSIONS];

	int reverse, original_number;

	/* a. Read and display an MxN matrix, mat consisting of integer numbers in main(). */

	// Read matrix from user.
	printf("Enter the size of Matrix: \n");
	scanf("%d %d", &M, &N);

	printf("\nEnter the elements: \n");
	for (int i = 0; i < M; i++) // Loop through the rows.
	{
		for (int j = 0; j < N; j++) // Loop through the columns.
		{
			scanf("%d", &mat[i][j]);
		}
	}

	// Display output.
	printf("\na. Entered elements: \n");
	for (int i = 0; i < M; i++) // Loop through the rows.
	{
		for (int j = 0; j < N; j++) // Loop through the columns.
		{
			printf(" %d \t", mat[i][j]);
		}
		printf("\n");
	}

	/* b. Replace every boundary elements by their reversed value
	and display the resultant matrix mat in the main program. */

	for (int i = 0; i < M; i++) // Loop through the rows.
	{
		for (int j = 0; j < N; j++) // Loop through the columns.
		{
			if ((i == 0) || (j == 0) || (i == M-1) || (j == N-1))
			{
				// The element is a boundary element.

				// Reverse the element.
				original_number = mat[i][j];
				reverse = 0; // Initialise.
				while (original_number > 0)
				{
					reverse = 10 * reverse + original_number % 10;
					original_number = original_number / 10;
				}
				mat[i][j] = reverse; // Update the value in the matrix.
			}
			else
			{
				// The element is NOT a boundary element.

				// Store the element to the 2D array: mat_non_boundary.
				mat_non_boundary[i-1][j-1] = mat[i][j];
			}
		}
	}

	// Display output.
	printf("\nb. After Boundary Elements Reverse: \n");
	for (int i = 0; i < M; i++) // Loop through the rows.
	{
		for (int j = 0; j < N; j++) // Loop through the columns.
		{
			printf(" %d \t", mat[i][j]);
		}
		printf("\n");
	}

	/* c. Store the non-boundary elements from “part b” in a 2D array. Write a function Replace()
		that accepts this 2D array as parameter and replaces all 2-digit elements by the sum of
		its digits. Display the resultant matrix in the main program. */

	Replace( M-2, N-2, mat_non_boundary );
		// Note that mat_non_boundary is of dimensions (M-2)x(N-2);

	// Display output.
	printf("\nc. After replacement: \n");
	for (int i = 0; i < M-2; i++) // Loop through the rows.
	{
		for (int j = 0; j < N-2; j++) // Loop through the columns.
		{
			printf(" %d \t", mat_non_boundary[i][j]);
		}
		printf("\n");
	}

	printf("\nMy name is Ashrith Sagar Yedlapalli and my registration number is 200902016.\n");

} // End.

void Replace( int row_dim, int col_dim, int matrix[MAX_DIMENSIONS][MAX_DIMENSIONS] )
{
	int sum_of_digits, original_number;

	for (int i = 0; i < row_dim; i++) // Loop through the rows.
	{
		for (int j = 0; j < col_dim; j++) // Loop through the columns.
		{
			// Check for 2-digit elements.
			if ((matrix[i][j] > 9) && (matrix[i][j] < 100))
			{
				// Find sum of digits of the element.
				original_number = matrix[i][j];
				sum_of_digits = 0; // Initialise.
				while (original_number > 0)
				{
					sum_of_digits += original_number % 10;
					original_number = original_number / 10;
				}
				matrix[i][j] = sum_of_digits; // Update the value in the matrix.
			}
		}
	}
}