Java Program to Print Downward Triangle Star Pattern
Last Updated :
29 Dec, 2022
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Downward triangle star pattern means we want to print a triangle that is downward facing means base is upwards and by default, orientation is leftwards so the desired triangle to be printed should look like
* * * * * * * * * *
Example
// Java Program to Print Lower Star Triangle Pattern
// Main class
public class GFG {
// Main driver method
public static void main(String[] args)
{
// Nested 2 for loops for iteration over the matrix
// Outer loop for rows
int rows = 9;
for (int a = rows - 1; a >= 0; a--) {
// Inner loop for columns
for (int b = 0; b <= a; b++) {
// Prints star and space
System.out.print("*"
+ " ");
}
// By now we are done with single row so new
// line
System.out.println();
}
}
}
Output
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Using Recursion
// added by Manish Sharma
import java.io.*;
class GFG
{
public static void printRow(int n)
{
if(n == 0) // base case
{
return;
}
System.out.print("* ");
printRow(n - 1); // next * in the same row
}
public static void nextRow(int n)
{
if(n == 0)
{
return;
}
printRow(n); // prints the whole row recursively.
System.out.print("\n"); // for new line after printing a row...
nextRow(n - 1); // changed to new row
}
public static void main (String[] args)
{
GFG.nextRow(5); // no need to create an object of GFG class as nextRow method is static.
}
}
Output
* * * * * * * * * * * * * * *
Time Complexity: O(n2), where n represents the given number of rows.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
