Example: Hollow Rectangle in C

// Hollow Rectangle
#include <stdio.h>

int main() {
    // Step 1: Declare variables for rows and columns
    int numRows, numCols;

    // Step 2: Prompt user for input
    printf("Enter the number of rows: ");
    scanf("%d", &numRows);
    printf("Enter the number of columns: ");
    scanf("%d", &numCols);

    // Step 3: Input validation
    if (numRows <= 0 || numCols <= 0) {
        printf("Dimensions must be positive integers.\n");
        return 1;
    }
    // Special case for very small rectangles that cannot be hollow
    if (numRows < 2 || numCols < 2) {
        printf("Minimum dimensions for a hollow rectangle are 2x2. Printing solid instead.\n");
        // Fallback to solid rectangle logic for small inputs if desired, or exit.
        // For this example, we'll still try to print based on the logic, which will be solid.
    }


    printf("\nYour hollow rectangle:\n");

    // Step 4: Outer loop for rows
    for (int i = 0; i < numRows; i++) {
        // Step 5: Inner loop for columns
        for (int j = 0; j < numCols; j++) {
            // Step 6: Conditional check to print '*' or ' '
            if (i == 0 || i == numRows - 1 || j == 0 || j == numCols - 1) {
                printf("*"); // Print '*' for border (first/last row, first/last column)
            } else {
                printf(" "); // Print ' ' for interior
            }
        }
        printf("\n");
    }

    return 0;
}