Question

write a loop profram in java to print the following series:-

15 14 13 12 11
7 8 9 10
6 5 4
3 2
1

Answer 1

Pattern in Java

We have a decreasing sequence of numbers in a triangle pattern.

Suppose there are n rows. Then there are a total of $\sf\dfrac{n(n+1)}{2}$ elements.

[This is because the number of elements = 1+2+3+...+n = $\sf\dfrac{n(n+1)}{2}$]

We run a loop with a variable i for n rows. And we have an inner loop which runs i times in each row. Alongside we keep on printing the pattern elements.

Here is a Java program:

public class Pattern

{

   public static void main(String[] args)

   {

       int n = 5;      //Number of Rows

       

       int k = (n*(n+1))/2;    //First Element in first row

       

       for(int i=n;i>0;i--)    //Loop to print n rows

       {

           for(int j=0;j<i;j++)    //Loop to print i elements in each row

           {

               System.out.print(k+" ");    //Printing k

               k--;                        //Decrementing k

           }

           System.out.println();   //Printing a new line after completion of a row

       }

   }

}

Answer 2

Answer:

123456789101112131415