Program to print hollow pyramid, diamond pattern and their modifications
Last Updated :
27 Mar, 2023
For Prerequisite : Loops, If Else Statement
1. Hollow pyramid/triangle pattern
The pattern is similar to pyramid pattern. The only difference is, we will replace all internal '#' or '*' characters by space character and we will print 2*N-1 (N = number of rows in pattern) '#' or '*' characters in last row.
Examples:
Input: n=6
Output:
#
# #
# #
# #
# #
# #
###########
C++14
// CPP program to print a hollow pyramid pattern
#include <iostream>
using namespace std;
void printPattern(int);
int main()
{
int n = 6;
printPattern(n);
}
void printPattern(int n)
{
int i, j, k = 0;
for (i = 1; i <= n; i++) // row=6
{
// Print spaces
for (j = i; j < n; j++) {
cout << " ";
}
// Print #
while (k != (2 * i - 1)) {
if (k == 0 || k == 2 * i - 2)
cout << "#";
else
cout << " ";
k++;
}
k = 0;
cout << endl; // print next row
}
// print last row
for (i = 0; i < 2 * n - 1; i++) {
cout << "#";
}
}
// this article is contributed by Shivani Ghughtyal
// JAVA program to print a hollow
// pyramid pattern
class GFG{
public static void main(String args[])
{
int n = 6;
printPattern(n);
}
static void printPattern(int n)
{
int i, j, k = 0;
for (i = 1; i <= n; i++) // row=6
{
// Print spaces
for (j = i; j < n; j++) {
System.out.print(" ");
}
// Print #
while (k != (2 * i - 1)) {
if (k == 0 || k == 2 * i - 2)
System.out.print("#");
else
System.out.print(" ");
k++;
;
}
k = 0;
// print next row
System.out.println();
}
// print last row
for (i = 0; i < 2 * n - 1; i++) {
System.out.print("#");
}
}
}
/*This code is contributed by Nikita Tiwari.*/
# Python program to print a hollow
# pyramid pattern
def printPattern( n) :
k = 0
for i in range(1,n+1) : #row 6
# Print spaces
for j in range(i,n) :
print(' ', end='')
# Print #
while (k != (2 * i - 1)) :
if (k == 0 or k == 2 * i - 2) :
print('#', end='')
else :
print(' ', end ='')
k = k + 1
k = 0;
print ("") # print next row
# print last row
for i in range(0, 2 * n -1) :
print ('#', end = '')
# Driver code
n = 6
printPattern(n)
# This code is contributed by Nikita Tiwari.
using System;
public class GFG{
public static void Main()
{
int n = 6;
printPattern(n);
}
static void printPattern(int n)
{
int i, j, k = 0;
for (i = 1; i <= n; i++) // row=6
{
// Print spaces
for (j = i; j < n; j++) {
Console.Write(" ");
}
// Print #
while (k != (2 * i - 1)) {
if (k == 0 || k == 2 * i - 2)
Console.Write("#");
else
Console.Write(" ");
k++;
;
}
k = 0;
// print next row
Console.WriteLine();
}
// print last row
for (i = 0; i < 2 * n - 1; i++) {
Console.Write("#");
}
}
}
// This code is contributed by laxmigangarajula03
<?php
// php program to print a
// hollow pyramid pattern
function printPattern($n)
{
$k = 0;
// row=6
for ($i = 1; $i <= $n; $i++)
{
// Print spaces
for ($j = $i; $j < $n; $j++)
{
echo " ";
}
// Print #
while ($k != (2 * $i - 1))
{
if ($k == 0 || $k == 2 *
$i - 2)
echo "#";
else
echo " ";
$k++;
}
$k = 0;
// print next row
echo "\n";
}
// print last row
for ($i = 0; $i < 2 * $n - 1; $i++)
{
echo "#";
}
}
//Driver Code
$n = 6;
printPattern($n);
// This code is contributed by mits
?>
<script>
// JavaScript program to print a hollow pyramid pattern
var n = 6;
printPattern(n);
function printPattern(n)
{
var i, j, k = 0;
for (i = 1; i <= n; i++)// row=6
{
// Print spaces
for (j = i; j < n; j++)
{
document.write(" ");
}
// Print #
while (k != 2 * i - 1)
{
if (k == 0 || k == 2 * i - 2)
document.write("#");
else
document.write(" ");
k++;
}
k = 0;
document.write("<br>"); // print next row
}
// print last row
for (i = 0; i < 2 * n - 1; i++)
{
document.write("#");
}
}
// This code is contributed by rdtank.
</script>
Output #
# #
# #
# #
# #
# #
###########
Time complexity: O(N^2),This algorithm has a time complexity of O(N^2), where N is the number of rows. This is because we are looping through the rows and columns of the pattern, which takes O(N^2) time to complete.
Space complexity: O(1),This algorithm does not require any additional space, so its space complexity is O(1).
2. Hollow Diamond
Note: For even input, print the pattern for n-1.
Example:
Input: 1
Output:
For n=1
Input: 7
Output:
For n=7
Input: 9
Output:
For n=9
Approach: To print diamond we need to print spaces before star and after the star to achieve constant increasing distance of stars.
To print the box shape we need to print '-' for i==1 (first row) & i==n (last row) and '|' for j==1 (first column) and j==n (last column).
Algorithm: 1. If n is odd increment n.
2. Find mid=n/2.
3. Traverse from 1 to mid to print upper half of the pattern (say i).
4. Traverse from 1 to mid-i to print spaces for upper left most outer box (say j).
5. If (i==1) print '*' (since for first row we need only one star).
6. else print '*' and traverse from 1 to 2*i-3 to print spaces for hollow diamond (say j) and print '*' after loop is over.
7. Traverse from 1 to mid-i to print spaces again for upper right most outer box (say j).
8. Close the loop at step 3.
9. Traverse from mid+1 to n-1 to print lower half of the pattern (say i).
4. Traverse from 1 to i-mid to print spaces for lower left most outer box (say j).
5. If (i==n-1) print '*' (since for last row we need only one star).
6. else print '*' and traverse from 1 to 2*(n-i)-3 to print spaces for hollow diamond (say j) and print '*' after loop is over.
7. Traverse from 1 to i-mid to print spaces again for lower right most outer box (say j).
8. Close the loop at step 9.
C++14
#include <bits/stdc++.h>
using namespace std;
// function to print the pattern
void printPattern(int& n)
{
int i,j,mid;
if(n%2==1) //when n is odd, increase it by 1 to make it even
n++;
mid = n/2;
// upper half pattern
for(i = 1; i<= mid; i++) {
for(j = 1; j<=mid-i; j++) //print the blank spaces and outer box before star
cout<<" ";
if(i == 1) {
cout << "*";
}else{
cout << "*"; //in each line star at start and end position
for(j = 1; j<=2*i-3; j++) { //print space to make hollow
cout << " ";
}
cout << "*";
}
for(j = 1; j<=mid-i; j++) //print the blank spaces and outer box after star
cout<<" ";
cout << endl;
}
// lower half pattern
for(i = mid+1; i<n; i++) {
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box before star
cout<<" ";
if(i == n-1) {
cout << "*";
}else{
cout << "*"; //in each line star at start and end position
for(j = 1; j<=2*(n - i)-3; j++) { //print space to make hollow
cout << " ";
}
cout << "*";
}
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box after star
cout<<" ";
cout << endl;
}
}
// driver's code
int main() {
int n=7;
printPattern(n);
}
// this code is contributed by prophet1999
// JAVA program
class GFG{
// function to print the pattern
static void printPattern(int n)
{
int i,j,mid;
if(n%2==1) //when n is odd, increase it by 1 to make it even
n++;
mid = n/2;
// upper half pattern
for(i = 1; i<= mid; i++) {
for(j = 1; j<=mid-i; j++) //print the blank spaces and outer box before star
System.out.print(" ");
if(i == 1) {
System.out.print("*");
}else{
System.out.print("*"); //in each line star at start and end position
for(j = 1; j<=2*i-3; j++) { //print space to make hollow
System.out.print(" ");
}
System.out.print("*");
}
for(j = 1; j<=mid-i; j++) //print the blank spaces and outer box after star
System.out.print(" ");
System.out.println();
}
// lower half pattern
for(i = mid+1; i<n; i++) {
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box before star
System.out.print(" ");
if(i == n-1) {
System.out.print("*");
}else{
System.out.print("*"); //in each line star at start and end position
for(j = 1; j<=2*(n - i)-3; j++) { //print space to make hollow
System.out.print(" ");
}
System.out.print("*");
}
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box after star
System.out.print(" ");
System.out.println();
}
}
// driver's code
public static void main(String args[])
{
int n = 7;
printPattern(n);
}
}
// This code is contributed by Pushpesh Raj.
// C# program
using System;
public class GFG{
// function to print the pattern
public static void printPattern(int n)
{
int i, j, mid;
if(n % 2 == 1) //when n is odd, increase it by 1 to make it even
n++;
mid = n/2;
// upper half pattern
for(i = 1; i <= mid; i++) {
for(j = 1; j <= mid - i; j++) //print the blank spaces and outer box before star
Console.Write(" ");
if(i == 1) {
Console.Write("*");
}else{
Console.Write("*"); //in each line star at start and end position
for(j = 1; j <= 2 * i - 3; j++) { //print space to make hollow
Console.Write(" ");
}
Console.Write("*");
}
for(j = 1; j <= mid - i; j++) //print the blank spaces and outer box after star
Console.Write(" ");
Console.WriteLine();
}
// lower half pattern
for(i = mid + 1; i < n; i++) {
for(j = 1; j <= i - mid; j++) //print the blank spaces and outer box before star
Console.Write(" ");
if(i == n - 1) {
Console.Write("*");
}else{
Console.Write("*"); //in each line star at start and end position
for(j = 1; j <= 2*(n - i)-3; j++) { //print space to make hollow
Console.Write(" ");
}
Console.Write("*");
}
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box after star
Console.Write(" ");
Console.WriteLine();
}
}
// driver's code
public static void Main()
{
int n = 7;
printPattern(n);
}
}
// This code is contributed by Aman Kumar.
// function to print the pattern
function printPattern( n)
{
let i,j,mid;
if(n % 2 == 1) //when n is odd, increase it by 1 to make it even
n++;
mid = n/2;
// upper half pattern
for(i = 1; i <= mid; i++) {
for(j = 1; j <= mid - i; j++) //print the blank spaces and outer box before star
console.log(" ");
if(i == 1) {
console.log("*");
}else{
console.log("*"); //in each line star at start and end position
for(j = 1; j<=2*i-3; j++) { //print space to make hollow
console.log(" ");
}
console.log("*");
}
for(j = 1; j<=mid-i; j++) //print the blank spaces and outer box after star
console.log(" ");
console.log("<br>");
}
// lower half pattern
for(i = mid+1; i<n; i++) {
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box before star
console.log(" ");
if(i == n-1) {
console.log("*");
}else{
console.log("*"); //in each line star at start and end position
for(j = 1; j<=2*(n - i)-3; j++) { //print space to make hollow
console.log(" ");
}
console.log("*");
}
for(j = 1; j<=i-mid; j++) //print the blank spaces and outer box after star
console.log(" ");
console.log("<br>");
}
}
// driver's code
let n=7;
printPattern(n);
# Python program
class GFG:
# function to print the pattern
@staticmethod
def printPattern(n):
i, j, mid = 0, 0, 0
if n % 2 == 1: #when n is odd, increase it by 1 to make it even
n += 1
mid = n // 2
# upper half pattern
for i in range(1, mid+1):
for j in range(1, mid-i+1): #print the blank spaces and outer box before star
print(" ", end="")
if i == 1:
print("*", end="")
else:
print("*", end="") #in each line star at start and end position
for j in range(1, 2*i-3+1): #print space to make hollow
print(" ", end="")
print("*", end="")
for j in range(1, mid-i+1): #print the blank spaces and outer box after star
print(" ", end="")
print()
# lower half pattern
for i in range(mid+1, n):
for j in range(1, i-mid+1): #print the blank spaces and outer box before star
print(" ", end="")
if i == n-1:
print("*", end="")
else:
print("*", end="") #in each line star at start and end position
for j in range(1, 2*(n-i)-3+1): #print space to make hollow
print(" ", end="")
print("*", end="")
for j in range(1, i-mid+1): #print the blank spaces and outer box after star
print(" ", end="")
print()
# driver's code
if __name__ == '__main__':
n = 7
GFG.printPattern(n)
# This code is contributed by sharmashivam215.
Output *
* *
* *
* *
* *
* *
*
Time Complexity: O(n^2) for given input n
Auxiliary Space: O(1)
3. Hollow Diamond bounded inside a rectangular box made of horizontal and vertical dashes(-).
Write a program to Print hollow diamond pattern bound inside a box made of dash(-) and bitwise-OR(|) as shown below.
Note: For even input, print the pattern for n-1.
Example:
Input: 1
Output:
For n=1
Input: 7
Output:
For n=7
Input: 9
Output:
For n=9
Approach: To print diamond we need to print spaces before star and after the star to achieve constant increasing distance of stars.
To print the box shape we need to print '-' for i==1 (first row) & i==n (last row) and '|' for j==1 (first column) and j==n (last column).
Algorithm: 1. If n is odd increment n.
2. Find mid=n/2.
3. Traverse from 1 to mid to print upper half of the pattern (say i).
4. Traverse from 1 to mid-i to print upper left most outer box (say j).
5. If (i==1) print '*' (since for first row we need only one star).
6. else print '*' and traverse from 1 to 2*i-3 to print spaces for hollow diamond (say j) and print '*' after loop is over.
7. Traverse from 1 to mid-i to print upper right most outer box (say j).
8. Close the loop at step 3.
9. Traverse from mid+1 to n-1 to print lower half of the pattern (say i).
4. Traverse from 1 to i-mid to print lower left most outer box (say j).
5. If (i==n-1) print '*' (since for last row we need only one star).
6. else print '*' and traverse from 1 to 2*(n-i)-3 to print spaces for hollow diamond (say j) and print '*' after loop is over.
7. Traverse from 1 to i-mid to print lower right most outer box (say j).
8. Close the loop at step 9.
C++14
#include <bits/stdc++.h>
using namespace std;
// function to print the pattern
void printPattern(int& n)
{
int i,j,mid;
if(n%2==1) //when n is odd, increase it by 1 to make it even
n++;
mid = n/2;
// upper half pattern
for(i = 1; i<= mid; i++) {
for(j = 1; j<=mid-i; j++) { //print the blank spaces and outer box before star
if(i==1)
cout<<"-";
else if(j==1)
cout << "|";
else cout<<" ";
}
if(i == 1) {
cout << "*";
}else{
cout << "*"; //in each line star at start and end position
for(j = 1; j<=2*i-3; j++) { //print space to make hollow
cout << " ";
}
cout << "*";
}
for(j = 1; j<=mid-i; j++) { //print the blank spaces and outer box after star
if(i==1)
cout<<"-";
else if(j==mid-i)
cout << "|";
else cout<<" ";
}
cout << endl;
}
// lower half pattern
for(i = mid+1; i<n; i++) {
for(j = 1; j<=i-mid; j++) { //print the blank spaces and outer box before star
if(i==n-1)
cout<<"-";
else if(j==1)
cout << "|";
else cout<<" ";
}
if(i == n-1) {
cout << "*";
}else{
cout << "*"; //in each line star at start and end position
for(j = 1; j<=2*(n - i)-3; j++) { //print space to make hollow
cout << " ";
}
cout << "*";
}
for(j = 1; j<=i-mid; j++) { //print the blank spaces and outer box after star
if(i==n-1)
cout<<"-";
else if(j==i-mid)
cout << "|";
else cout<<" ";
}
cout << endl;
}
}
// driver's code
int main() {
int n=12;
printPattern(n);
}
// this code is contributed by prophet1999
// Java code to implement the above approach
import java.io.*;
import java.util.*;
class GFG
{
// function to print the pattern
public static void printPattern(int n)
{
int i,j,mid;
if(n%2==1) //when n is odd, increase it by 1 to make it even
n++;
mid = n/2;
// upper half pattern
for(i = 1; i<= mid; i++) {
for(j = 1; j<=mid-i; j++) { //print the blank spaces and outer box before star
if(i==1)
System.out.print("-");
else if(j==1)
System.out.print("|");
else
System.out.print(" ");
}
if(i == 1) {
System.out.print("*");
}
else{
System.out.print("*"); //in each line star at start and end position
for(j = 1; j<=2*i-3; j++) { //print space to make hollow
System.out.print(" ");
}
System.out.print("*");
}
for(j = 1; j<=mid-i; j++) { //print the blank spaces and outer box after star
if(i==1)
System.out.print("-");
else if(j==mid-i)
System.out.print("|");
else System.out.print(" ");
}
System.out.print("\n");
}
// lower half pattern
for(i = mid+1; i<n; i++) {
for(j = 1; j<=i-mid; j++) { //print the blank spaces and outer box before star
if(i==n-1)
System.out.print("-");
else if(j==1)
System.out.print("|");
else System.out.print(" ");
}
if(i == n-1) {
System.out.print("*");
}else{
System.out.print("*"); //in each line star at start and end position
for(j = 1; j<=2*(n - i)-3; j++) { //print space to make hollow
System.out.print(" ");
}
System.out.print("*");
}
for(j = 1; j<=i-mid; j++) { //print the blank spaces and outer box after star
if(i==n-1)
System.out.print("-");
else if(j==i-mid)
System.out.print("|");
else System.out.print(" ");
}
System.out.print("\n");
}
}
// Driver Code
public static void main(String[] args)
{
int n=12;
printPattern(n);
}
}
//this code is contributed by adityapatil12
# function to print the pattern
def printPattern(n):
if n % 2 == 1: # when n is odd, increase it by 1 to make it even
n += 1
mid = n // 2
# upper half pattern
for i in range(1, mid+1):
for j in range(1, mid-i+1): # print the blank spaces and outer box before star
if i == 1:
print("-", end="")
elif j == 1:
print("|", end="")
else:
print(" ", end="")
if i == 1:
print("*", end="")
else:
print("*", end="") # in each line star at start and end position
for j in range(1, 2*i-2): # print space to make hollow
print(" ", end="")
print("*", end="")
for j in range(1, mid-i+1): # print the blank spaces and outer box after star
if i == 1:
print("-", end="")
elif j == mid-i:
print("|", end="")
else:
print(" ", end="")
print()
# lower half pattern
for i in range(mid+1, n):
for j in range(1, i-mid+1): # print the blank spaces and outer box before star
if i == n-1:
print("-", end="")
elif j == 1:
print("|", end="")
else:
print(" ", end="")
if i == n-1:
print("*", end="")
else:
print("*", end="") # in each line star at start and end position
for j in range(1, 2*(n-i)-2): # print space to make hollow
print(" ", end="")
print("*", end="")
for j in range(1, i-mid+1): # print the blank spaces and outer box after star
if i == n-1:
print("-", end="")
elif j == i-mid:
print("|", end="")
else:
print(" ", end="")
print()
# driver's code
n = 12
printPattern(n)
# This code is contributed by prasad264
using System;
namespace Pattern
{
class Program
{
static void PrintPattern(ref int n)
{
int i, j, mid;
if (n % 2 == 1) //when n is odd, increase it by 1 to make it even
n++;
mid = n / 2;
// upper half pattern
for (i = 1; i <= mid; i++)
{
for (j = 1; j <= mid - i; j++)
{ //print the blank spaces and outer box before star
if (i == 1)
Console.Write("-");
else if (j == 1)
Console.Write("|");
else Console.Write(" ");
}
if (i == 1)
{
Console.Write("*");
}
else
{
Console.Write("*"); //in each line star at start and end position
for (j = 1; j <= 2 * i - 3; j++)
{ //print space to make hollow
Console.Write(" ");
}
Console.Write("*");
}
for (j = 1; j <= mid - i; j++)
{ //print the blank spaces and outer box after star
if (i == 1)
Console.Write("-");
else if (j == mid - i)
Console.Write("|");
else Console.Write(" ");
}
Console.WriteLine();
}
// lower half pattern
for (i = mid + 1; i < n; i++)
{
for (j = 1; j <= i - mid; j++)
{ //print the blank spaces and outer box before star
if (i == n - 1)
Console.Write("-");
else if (j == 1)
Console.Write("|");
else Console.Write(" ");
}
if (i == n - 1)
{
Console.Write("*");
}
else
{
Console.Write("*"); //in each line star at start and end position
for (j = 1; j <= 2 * (n - i) - 3; j++)
{ //print space to make hollow
Console.Write(" ");
}
Console.Write("*");
}
for (j = 1; j <= i - mid; j++)
{ //print the blank spaces and outer box after star
if (i == n - 1)
Console.Write("-");
else if (j == i - mid)
Console.Write("|");
else Console.Write(" ");
}
Console.WriteLine();
}
}
static void Main(string[] args)
{
int n = 12;
PrintPattern(ref n);
}
}
}
// This code is contributed by factworx412
// JavaScript code to implement the above approach
// function to print the pattern
function printPattern(n) {
let i, j, mid;
if (n % 2 === 1) { // when n is odd, increase it by 1 to make it even
n++;
}
mid = n / 2;
// upper half pattern
for (i = 1; i <= mid; i++) {
let line = "";
for (j = 1; j <= mid - i; j++) { // print the blank spaces and outer box before star
if (i === 1) {
line += "-";
}
else if (j === 1) {
line += "|";
}
else {
line += " ";
}
}
if (i === 1) {
line += "*";
}
else {
line += "*"; // in each line star at start and end position
for (j = 1; j <= 2 * i - 3; j++) { // print space to make hollow
line += " ";
}
line += "*";
}
for (j = 1; j <= mid - i; j++) { // print the blank spaces and outer box after star
if (i === 1) {
line += "-";
}
else if (j === mid - i) {
line += "|";
}
else {
line += " ";
}
}
console.log(line);
}
// lower half pattern
for (i = mid + 1; i < n; i++) {
let line = "";
for (j = 1; j <= i - mid; j++) { // print the blank spaces and outer box before star
if (i === n - 1) {
line += "-";
}
else if (j === 1) {
line += "|";
}
else {
line += " ";
}
}
if (i === n - 1) {
line += "*";
}
else {
line += "*"; // in each line star at start and end position
for (j = 1; j <= 2 * (n - i) - 3; j++) { // print space to make hollow
line += " ";
}
line += "*";
}
for (j = 1; j <= i - mid; j++) { // print the blank spaces and outer box after star
if (i === n - 1) {
line += "-";
}
else if (j === i - mid) {
line += "|";
}
else {
line += " ";
}
}
console.log(line);
}
}
// Driver Code
let n = 12;
printPattern(n);
Output-----*-----
| * * |
| * * |
| * * |
|* *|
* *
|* *|
| * * |
| * * |
| * * |
-----*-----
Time Complexity: O(n*n)
Auxiliary Space: O(1)
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