Example: Hollow Star Diamond in C

// Hollow Star Diamond
#include <stdio.h>

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

    // Step 1: Get user input for the number of rows (center width)
    printf("Enter the number of rows for the hollow diamond (odd number recommended): ");
    scanf("%d", &n);

    // Step 2: Print the upper half of the hollow diamond
    for (i = 1; i <= n; i++) {
        // Print leading spaces
        for (j = 1; j <= n - i; j++) {
            printf(" ");
        }
        // Print stars for the current row
        for (j = 1; j <= 2 * i - 1; j++) {
            // Print star only at the first position, last position, or if it's the first row
            if (j == 1 || j == 2 * i - 1) {
                printf("*");
            } else {
                printf(" ");
            }
        }
        printf("\n");
    }

    // Step 3: Print the lower half of the hollow diamond
    for (i = n - 1; i >= 1; i--) {
        // Print leading spaces
        for (j = 1; j <= n - i; j++) {
            printf(" ");
        }
        // Print stars for the current row
        for (j = 1; j <= 2 * i - 1; j++) {
            // Print star only at the first position or last position
            if (j == 1 || j == 2 * i - 1) {
                printf("*");
            } else {
                printf(" ");
            }
        }
        printf("\n");
    }

    return 0;
}