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
// Java Program to Print Lower Star Triangle Pattern// Main classpublic 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
Java
// added by Manish Sharmaimport 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.
