Spiral_Matrix.c

/*Spiral Matrix
Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
*/
#include <stdio.h>

void spiral_matrix(int[][10], int, int);
int main()
{
	int ROW, COLUMN, is_null = 0;

	printf("Enter Row: ");
	scanf("%d", &ROW);

	printf("Enter column: ");
	scanf("%d", &COLUMN);

	int matrix[10][10];

	for (int i = 0; i < ROW; i++)
	{
		for (int j = 0; j < COLUMN; j++)
		{
			scanf("%d", &matrix[i][j]);
			if (matrix[i][j] == 0)
				is_null++;
		}
	}

	if (is_null == ROW *COLUMN)
	{
		printf("\nNull Matrix\n");
	}
	else
	{
		printf("Entered Matrix:\n");
		for (int i = 0; i < ROW; i++)
		{
			printf("\n");
			for (int j = 0; j < COLUMN; j++)
			{
				printf("%d", matrix[i][j]);
				printf("\t");
			}
		}

		spiral_matrix(matrix, ROW, COLUMN);
	}

	return 0;
}

// Prints the spiral matrix of the given matrix
void spiral_matrix(int matrix[][10], int ROW, int COLUMN)
{
	printf("\n\nSpiral Order Of the Matrix: \t");
	int i;
	int first_row = 0, first_column = 0;

	while (first_row < ROW && first_column < COLUMN)
	{
		/*Print the first row from the remaining rows */
		for (i = first_column; i < COLUMN; ++i)
		{
			printf("%d ", matrix[first_row][i]);
		}

		first_row++;

		/*Print the last column from the remaining columns */
		for (i = first_row; i < ROW; ++i)
		{
			printf("%d ", matrix[i][COLUMN - 1]);
		}

		COLUMN--;

		/*Print the last row from the remaining rows */
		if (first_row < ROW)
		{
			for (i = COLUMN - 1; i >= first_column; --i)
			{
				printf("%d ", matrix[ROW - 1][i]);
			}

			ROW--;
		}

		/*Print the first column from the remaining columns */
		if (first_column < COLUMN)
		{
			for (i = ROW - 1; i >= first_row; --i)
			{
				printf("%d ", matrix[i][first_column]);
			}

			first_column++;
		}
	}
}

/*
Sample Output
Enter Rows:2
Enter Column: 2
1	2
3	4

Entered Matrix:
1	2 
3 	4

Spiral Order of the Matrix: 1 2 4 3

Time Complexity: O(ROW*COLUMN)
Space Complexity:O(1).

*/