Java Exercises: Form a staircase shape of n coins where every k-th row must have exactly k coins

Java Basic: Exercise-109 with Solution

Write a Java program to form a staircase shape of n coins where every k-th row must have exactly k coins.

Example 1:
n = 3
The coins can form the following rows:
$
$ $
We will return 2 rows.
Example 2:
n = 4
The coins can form the following rows:
$
$ $
$
We will return 2 rows as the 3rd row is incomplete.
Example 3:
n = 5
The coins can form the following rows:
$
$ $
$ $
We will return 2 rows as the 3rd row is incomplete.

Sample Solution:

Java Code:

import java.util.Scanner;
public class Example109 {
     public static void main(String[] arg) {
	  Scanner in = new Scanner(System.in);	
       System.out.print("Input a positive integer: ");
        int n = in.nextInt(); 
		if (n>0)
		{
           System.out.println("Number of rows: "+((int)((Math.sqrt(8 * (long)n + 1) - 1) / 2)));	
		}       	
	}	
}

Sample Output:

Input a positive integer: 5                                            
Number of rows: 2 

Flowchart:

Java Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a Java program to add all the digits of a given positive integer until the result has a single digit.
Next: Write a Java program to check whether an given integer is a power of 4 or not.