The Hollow Hourglass Pattern is a symmetrical pattern that resembles an hourglass but with hollow spaces inside and only edges having characters. In this article, we will learn how to print the Hollow Hourglass Pattern using a C program.
Program to Print Hollow Hourglass Pattern in C
#include <stdio.h>
int main() {
int n = 5;
// Outer loop to iterate through each row
for (int i = 0; i < 2 * n - 1; i++) {
// Determine the row level relative to the center
int l = (i < n) ? i : 2 * n - 2 - i;
// Print leading spaces
for (int j = 0; j < l; j++) {
printf(" ");
}
// Print stars and hollow spaces in the current row
for (int k = 0; k < 2 * (n - l) - 1; k++) {
if (k == 0 || k == 2 * (n - l) - 2 || i == 0
|| i == 2 * n - 2)
printf("* ");
else
printf(" ");
}
printf("\n");
}
return 0;
}
#include <stdio.h>
int main() {
int n = 5;
// Outer loop to iterate through each row
for (int i = 0; i < 2 * n - 1; i++) {
// Determine the row level relative to the center
int l = (i < n) ? i : 2 * n - 2 - i;
// Print leading spaces
for (int j = 0; j < l; j++) {
printf(" ");
}
// Print stars and hollow spaces in the current row
for (int k = 0; k < 2 * (n - l) - 1; k++) {
if (k == 0 || k == 2 * (n - l) - 2 || i == 0
|| i == 2 * n - 2)
printf("%d ", k + 1);
else
printf(" ");
}
printf("\n");
}
return 0;
}
#include <stdio.h>
int main() {
int n = 5;
// Outer loop to iterate through each row
for (int i = 0; i < 2 * n - 1; i++) {
// Determine the row level relative to the center
int l = (i < n) ? i : 2 * n - 2 - i;
// Print leading spaces
for (int j = 0; j < l; j++) {
printf(" ");
}
// Print stars and hollow spaces in the current row
for (int k = 0; k < 2 * (n - l) - 1; k++) {
if (k == 0 || k == 2 * (n - l) - 2 || i == 0
|| i == 2 * n - 2)
printf("%c ", k + 'A');
else
printf(" ");
}
printf("\n");
}
return 0;
}
Output
* * * * * * * * * | 1 2 3 4 5 6 7 8 9 | A B C D E F G H I
* * | 1 7 | A G
* * | 1 5 | A E
* * | 1 3 | A C
* | 1 | A
* * | 1 3 | A C
* * | 1 5 | A E
* * | 1 7 | A G
* * * * * * * * * | 1 2 3 4 5 6 7 8 9 | A B C D E F G H I
Explanation:
- The outer loop prints each row i.e. 2 * n - 1 rows.
- The l variable determines the relative position of the current row from the top or bottom center:
- Top half: l = i.
- Bottom half: l = 2 * n - 2 - i.
- The leading spaces are printed by the first inner loop according to the level
- The top and bottom boundaries are printed by the second inner loop using condition: i == 0 || i == 2 * n - 2
- The condition k == 0 || k == 2 * (n - l) - 2 ensures stars at the boundaries of each row for inner rows.