Java Program to Print Lower Triangular Matrix Number Pattern

by

Printing Lower Triangular Matrix Number Pattern

In the previous article, we have discussed Java Program to Print Matrix in Snake Number Pattern

In this article we will see how to print lower triangular matrix number patter.

While array elements are { 1, 2, 3, 4, 5, 6 }
1 0 0 0 0 0
1 2 0 0 0 0
1 2 3 0 0 0
1 2 3 4 0 0
1 2 3 4 5 6

Don’t stop learning now. Get hold of all the important Java fundamentals with the Simple java program example guide and practice well.

Approach :

  • Declare a array.
  • Calculate its length which will be the dimension of matrix i.e array_length*array_length.
  • Create the n*n matrix according to array.
  • Take a outer for loop to iterate row value.
  • Take a inner for loop to iterate column value.
  • For each iteration if row value > column value then store the column value at its coordinate else store 0 .
  • Print the updated matrix.

Java Code to Print Lower Triangular Matrix Number Pattern

import java.io.*;
class Main
{
    public static void main(String[] args)
    {
        //declaring a array
        int arr[] = { 1, 2, 3, 4, 5, 6 },numberOfRows , numberOfColumns;
        // taking the dimension of the square of the matrix as size 
        // and array elements willbe printed as the values of the lower triangular
        int size = arr.length;
        // declaring n*n matrix according to dimension 
        int b[][] = new int[size][size];
// first outer loop will iterate 0 to size.( dimension)
        for (  numberOfRows = 0; numberOfRows < size; numberOfRows++)
        {
    // first inner loop will iterate 0 to size.( dimension)
            for (  numberOfColumns = 0; numberOfColumns < size; numberOfColumns++)
                // if i > j then insert arr[j] in 2D array 
                if (numberOfRows >= numberOfColumns)
                    b[numberOfRows][numberOfColumns] = arr[numberOfColumns];
                else
                    // insert zero in array  
                    b[numberOfRows][numberOfColumns] = 0;
        }
        // printing pattern in 2-D array 
        for (  numberOfRows = 0; numberOfRows < size; numberOfRows++)
        {
            for (  numberOfColumns = 0; numberOfColumns < size; numberOfColumns++)
                System.out.print(b[numberOfRows][numberOfColumns] +" ");
            System.out.println();
        }
    }
 }


Output :

1 0 0 0 0 0
1 2 0 0 0 0
1 2 3 0 0 0
1 2 3 4 0 0
1 2 3 4 5 6

C Code to Print Lower Triangular Matrix Number Pattern

#include <stdio.h>
#include <stdlib.h>
int main()
{
        int arr[] = { 1, 2, 3, 4, 5, 6 },size, numberOfRows , numberOfColumns,arraySize,intSize;
        arraySize = sizeof(arr);
        intSize = sizeof(arr[0]);
        size = arraySize / intSize;
        int b[size][size]  ;
        for (  numberOfRows = 0; numberOfRows < size; numberOfRows++)
        {
            for (  numberOfColumns = 0; numberOfColumns < size; numberOfColumns++)
                if (numberOfRows >= numberOfColumns)
                    b[numberOfRows][numberOfColumns] = arr[numberOfColumns];
                else
                    b[numberOfRows][numberOfColumns] = 0;
        }
        for (  numberOfRows = 0; numberOfRows < size; numberOfRows++)
        {
            for (  numberOfColumns = 0; numberOfColumns < size; numberOfColumns++)
                printf("%d ",b[numberOfRows][numberOfColumns] );
             printf("\n");
        }
    return 0;
}

Output :

1 0 0 0 0 0
1 2 0 0 0 0
1 2 3 0 0 0
1 2 3 4 0 0
1 2 3 4 5 6

C++ Code to Print Lower Triangular Matrix Number Pattern

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int arr[] = { 1, 2, 3, 4, 5, 6 },size, numberOfRows , numberOfColumns,arraySize,intSize;
        arraySize = sizeof(arr);
        intSize = sizeof(arr[0]);
        size = arraySize / intSize;
        int b[size][size]  ;
        for (  numberOfRows = 0; numberOfRows < size; numberOfRows++)
        {
            for (  numberOfColumns = 0; numberOfColumns < size; numberOfColumns++)
                if (numberOfRows >= numberOfColumns)
                    b[numberOfRows][numberOfColumns] = arr[numberOfColumns];
                else
                    b[numberOfRows][numberOfColumns] = 0;
        }
        for (  numberOfRows = 0; numberOfRows < size; numberOfRows++)
        {
            for (  numberOfColumns = 0; numberOfColumns < size; numberOfColumns++)
                cout << b[numberOfRows][numberOfColumns] << " ";
            cout << endl;
        }
    return 0;
}


Output :

1 0 0 0 0 0
1 2 0 0 0 0
1 2 3 0 0 0
1 2 3 4 0 0
1 2 3 4 5 6

Are you seeking professional help for coding in the Java programming language? The tutorial of Java Programming Examples for beginners and experts will strongly improve your coding skills then you can program for any logic in Java.

Related Java Number Pattern Programs: