C Exercises: Reads the side of a square and prints a hollow square using hash (#) character

Last update on September 18 2025 12:35:02 (UTC/GMT +8 hours)

Print a hollow square of size nnn using #

Write a C program that reads the side (side sizes between 1 and 10 ) of a square and prints a hollow square using the hash (#) character.

Sample Input: 10

Sample Solution:

C Code:

#include <stdio.h>

int main()
{
    // Declare variables
int size, i, j;

    // Prompt user for input
printf("Input the size of the square: ");

    // Read the size from user
scanf("%d", &size);

    // Check if size is within valid range
if (size < 1 || size > 10) {
printf("Size should be in the range 1 to 10\n");
return 0; // Exit program if size is invalid
    }

    // Loop for rows
for (i = 0; i< size; i++) 
    {
        // Loop for columns
for (j = 0; j < size; j++) 
        {
            // Check if it's a border or inside space
if (i == 0 || i == size - 1)
printf("#"); // Print border
else if (j == 0 || j == size - 1)
printf("#"); // Print border
else
printf(" "); // Print space for inside
        }
printf("\n"); // Move to the next line after each row is printed
    }

return 0; // Indicate successful execution of the program
}

Sample Output:

Input the size of the square: 
##########
#        #
#        #
#        #
#        #
#        #
#        #
#        #
#        #
##########

Pictorial Presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C program to print a hollow square pattern of a given size, ensuring only the borders are printed.
• Write a C program to generate a hollow square with alternating border characters using loops.
• Write a C program to print a hollow square pattern and replace the diagonal with a different character.
• Write a C program to draw a hollow square by calculating and printing the appropriate spaces and hash symbols.

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