This article will guide you through the process of printing a Pyramid star pattern in Java.
1. Simple pyramid pattern
Java
import java.io.*;// Java code to demonstrate Pyramid star patternspublic 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
Java
/*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.
Java
import java.io.*;// 180 flipped pyramid star patternpublic 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:
Java
import java.io.*;// Java code to demonstrate star patternpublic 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
Java
/*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
Java
/*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
Java
/*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.