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);
}
} |
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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...
}
} |
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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);
}
} |
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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);
}
} |
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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();
}
}
} |
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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();
}
}
} |
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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...
}
} |
* * * * * * * * * * * * * * *
Time Complexity: O(n2), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.