Question

Program to display the lower triangular matrix
(Lower triangular matrix is a square matrix in which all the elements above the principle diagonal will be zero)

Matrix  = [9, 8, 7]
          [6, 5, 4]
          [3, 2, 1]

LOWER TRIANGULAR Matrix
[9, 0, 0]
[6, 5, 0]
[3, 2, 1]

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Code

import java.util.Scanner;
public class LowerTriangularMatrix
{
    public static void main(String[] args)
    {
        int row=0, col=0,i=0,j=0;
        int a[][];


        Scanner sc=new Scanner(System.in);
        System.out.println("ENTER THE ROW OF MATRIX");
        row=sc.nextInt();
        System.out.println("ENTER THE COLUMN OF MATRIX");
        col=sc.nextInt();

        if(row!=col)
        {
            System.out.println("MATRIX NEED TO BE SQUARE MATRIX FIRST!!!");
        }

        else
        {
            a=new int[row][col];
            System.out.println("ENTER THE ELEMENTS IN MATRIX");
            for(i=0;i< row;i++)
            {
                for(j=0;j< col;j++)
                {
                    a[i][j]=sc.nextInt();
                }
            }



            /*if j > i then print 0 else print number present in  array at that position */
            System.out.println("LOWER TRIANGULAR MATRIX");

            for(i=0;i< row;i++)
            {
                for(j=0;j< col;j++)
                {
                    if(j > i)
                    {
                        System.out.print("0 ");

                    }
                    else
                    {
                        System.out.print(a[i][j]+" ");
                    }

                }
                System.out.println();
            }

        }

    }
}