int printf(char* format, ...);


int main() {
    int n = 5; // height of the diamond
    int i;
    int j;

    // upper half of the diamond
    for (i = 1; i <= n; i++) {
        for (j = i; j < n; j++) {
            printf(" ");
        }
        for (j = 1; j <= (2 * i - 1); j++) {
            printf("*");
        }
        printf("\n");
    }

    // lower half of the diamond
    for (i = n - 1; i >= 1; i--) {
        for (j = n; j > i; j--) {
            printf(" ");
        }
        for (j = 1; j <= (2 * i - 1); j++) {
            printf("*");
        }
        printf("\n");
    }
}