Java Program to Print Pyramid Star Pattern
Last Updated :
29 Dec, 2022
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This article will guide you through the process of printing a Pyramid star pattern in Java.
1. Simple pyramid pattern
import java.io.*;
// Java code to demonstrate Pyramid star patterns
public class GeeksForGeeks {
// Function to demonstrate printing pattern
public static void PyramidStar(int n)
{
int a, b;
// outer loop to handle number of rows
// k in this case
for (a = 0; a < n; a++) {
// inner loop to handle number of columns
// values changing acc. to outer loop
for (b = 0; b <= a; b++) {
// printing stars
System.out.print("* ");
}
// end-line
System.out.println();
}
}
// Driver Function
public static void main(String args[])
{
int k = 5;
PyramidStar(k);
}
}
Output
* * * * * * * * * * * * * * *
By Recursion
/*package whatever //do not write package name here */
import java.io.*;
class GFG
{
// similar to inner for loop
public static void printRow(int n)
{
if(n == 0)
{
return;
}
System.out.print("* ");
printRow(n - 1); // recursive call for printing desired numbers of stars in a single row
}
// similar to outer for loop
public static void changeRow(int n) // for number of rows.....it prints stars for each row
{
if(n == 0)
{
return;
}
changeRow(n - 1); // recursive call for next row..
printRow(n); // prints stars in a single row..
System.out.print("\n"); // for changing the row....new line
}
public static void main (String[] args)
{
GFG.changeRow(5); // no need of object as changeRow is static method...
}
}
Output
* * * * * * * * * * * * * * *
Time Complexity: O(n2), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
2. After 180 degrees rotation/Mirrored pattern
Here we will print a star pyramid with a rotation of 180 degrees.
import java.io.*;
// 180 flipped pyramid star pattern
public class GFG {
// Function to demonstrate printing pattern
public static void FlippedPyramidStar(int k)
{
int a, b;
// 1st loop
for (a = 0; a < k; a++) {
// nested 2nd loop
for (b = 2 * (k - a); b >= 0; b--) {
// printing spaces
System.out.print(" ");
}
// nested 3rd loop
for (b = 0; b <= a; b++) {
// printing stars
System.out.print("* ");
}
// end-line
System.out.println();
}
}
// Driver Function
public static void main(String args[])
{
int k = 5;
FlippedPyramidStar(k);
}
}
Output
*
* *
* * *
* * * *
* * * * * Time Complexity: O(n2), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
3. Printing Triangles:
import java.io.*;
// Java code to demonstrate star pattern
public class GeeksForGeeks {
// Function to demonstrate printing pattern
public static void printTriangle(int n)
{
// outer loop to handle number of rows
// n in this case
for (int i = 0; i < n; i++) {
// inner loop to handle number spaces
// values changing acc. to requirement
for (int j = n - i; j > 1; j--) {
// printing spaces
System.out.print(" ");
}
// inner loop to handle number of columns
// values changing acc. to outer loop
for (int j = 0; j <= i; j++) {
// printing stars
System.out.print("* ");
}
// ending line after each row
System.out.println();
}
}
// Driver Function
public static void main(String args[])
{
int n = 5;
printTriangle(n);
}
}
Output
* * * * * * * * * * * * * * *
4-Star pattern
/*package whatever //do not write package name here */
import java.io.*;
class GFG {
public static void main (String[] args) {
for (int i=0;i<5;i++)
{
for (int j=0;j<5;j++)
{
System.out.print("*");
}
System.out.println();
}
}
}
Output
***** ***** ***** ***** *****
5- Another different Star pattern
/*package whatever //do not write package name here */
import java.io.*;
class GFG {
public static void main (String[] args) {
int n=5;
for (int i=n;i>=1;i--)
{
for (int j=i;j>=1;j--)
{
System.out.print("* ");
}
System.out.println();
}
}
}
Output
* * * * * * * * * * * * * * *
By Recursion
/*package whatever //do not write package name here */
import java.io.*;
class GFG
{
// similar to inner for loop
public static void printRow(int n)
{
if(n == 0)
{
return;
}
System.out.print("* ");
printRow(n - 1); // recursive call for printing desired numbers of stars in a single row
}
// similar to outer for loop
public static void changeRow(int n) // for number of rows.....it prints stars for each row
{
if(n == 0)
{
return;
}
printRow(n); // prints stars in a single row..
System.out.print("\n"); // for changing the row....new line
changeRow(n - 1); // recursive call for next row..
}
public static void main (String[] args)
{
GFG.changeRow(5); // no need of object as changeRow is static method...
}
}
Output
* * * * * * * * * * * * * * *
Time Complexity: O(n2), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
