C Program to Print Alphabet R Pattern

In this article, we will show how to write a C program to print the Alphabet R pattern or shape of stars using for loop, while loop, and functions.

#include <stdio.h>

int main()
{
	int rows;

	printf("Enter Rows = ");
	scanf("%d", &rows);

	for (int i = 0; i < rows; i++)
	{
		for (int j = 0; j < rows; j++)
		{
			if ((i == 0 || i == rows / 2) && (0 < j < rows - 1))
			{
				printf("*");
			}
			else if ((i != 0) && (j == 0 || (j == rows - 1 && i < rows / 2 )))
			{
				printf("*");
			}
			else if(j == i && i >= rows / 2)
			{
				printf("*");
			}
			else
			{
				printf(" ");
			}
		}
		printf("\n");
	}
	return 0;
}

Enter Rows = 16
**********
*              *
*              *
*              *
*              *
*              *
*              *
*              *
**********
*        *      
*         *     
*          *    
*           *   
*            *  
*             * 
*              *

Instead of a for loop, this Alphabet R Pattern of stars program uses a while loop to iterate the rows and columns. For more star programs, click here.

#include <stdio.h>

int main()
{
	int i, j, rows;

	printf("Enter Rows = ");
	scanf("%d", &rows);

	i = 0;
	while ( i < rows)
	{
		j = 0;
		while ( j < rows)
		{
			if (i == 0 && (0 < j < rows - 1))
			{
				printf("*");
			}
			else if (i != 0 && j == 0)
			{
				printf("*");
			}
			else if (i == rows / 2 && j != rows - 1)
			{
				printf("*");
			}
			else if (i != 0 && j == rows - 1 && i < rows / 2)
			{
				printf("*");
			}
			else if(j == i && i >= rows / 2)
			{
				printf("*");
			}
			else
			{
				printf(" ");
			}
			j++;
		}
		printf("\n");
		i++;
	}
	return 0;
}

Enter Rows = 17
***********
*               *
*               *
*               *
*               *
*               *
*               *
*               *
***********
*        *       
*         *      
*          *     
*           *    
*            *   
*             *  
*              * 
*               *

In this C program, we create an alphabetRPat function that accepts those values and prints the Alphabet R shape or Pattern of the given char.

#include <stdio.h>

void alphabetRPat(int rows, char a)
{
	for (int i = 0; i < rows; i++)
	{
		for (int j = 0; j < rows; j++)
		{
			if ((i == 0 || i == rows / 2) && (0 < j < rows - 1))
			{
				printf("%c", a);
			}
			else if ((i != 0) && (j == 0 || (j == rows - 1 && i < rows / 2 )))
			{
				printf("%c", a);
			}
			else if(j == i && i >= rows / 2)
			{
				printf("%c", a);
			}
			else
			{
				printf(" ");
			}
		}
		printf("\n");
	}
}

int main() {
	int rows;
	char a;

	printf("Enter Alphabet =  ");
	scanf("%c", &a);

	printf("Enter Rows = ");
	scanf("%d", &rows);

	alphabetRPat(rows, a);
	return 0;
}