Program to check if matrix is upper triangular

Given a square matrix and the task is to check the matrix is in upper triangular form or not. A square matrix is called upper triangular if all the entries below the main diagonal are zero.

Examples:

Input : mat[4][4] = {{1, 3, 5, 3},
                     {0, 4, 6, 2},
                     {0, 0, 2, 5},
                     {0, 0, 0, 6}};
Output : Matrix is in Upper Triangular form.

Input : mat[4][4] = {{5, 6, 3, 6},
                     {0, 4, 6, 6},
                     {1, 0, 8, 5},
                     {0, 1, 0, 6}};
Output : Matrix is not in Upper Triangular form.

C++

filter_none

edit
close

play_arrow

link
brightness_4
code

// Program to check upper triangular matrix.
#include <bits/stdc++.h>
#define N 4
using namespace std;
  
// Function to check matrix is in upper triangular
// form or not.
bool isUpperTriangularMatrix(int mat[N][N])
{
    for (int i = 1; i < N; i++)
        for (int j = 0; j < i; j++)
            if (mat[i][j] != 0)
                return false;
    return true;
}
  
// Driver function.
int main()
{
    int mat[N][N] = { { 1, 3, 5, 3 },
                      { 0, 4, 6, 2 },
                      { 0, 0, 2, 5 },
                      { 0, 0, 0, 6 } };
    if (isUpperTriangularMatrix(mat))
        cout << "Yes";
    else
        cout << "No";
    return 0;
}

chevron_right


Java

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java Program to check upper 
// triangular matrix.
import java.util.*;
import java.lang.*;
  
public class GfG
{
    private static final int N = 4;
  
    // Function to check matrix is in
    // upper triangular form or not.
    public static Boolean isUpperTriangularMatrix(int mat[][])
    {
        for (int i = 1; i < N ; i++)
            for (int j = 0; j < i; j++)
                if (mat[i][j] != 0)
                    return false;
        return true;
    
      
    // driver function
    public static void main(String argc[]){
        int[][] mat= { { 1, 3, 5, 3 },
                       { 0, 4, 6, 2 },
                       { 0, 0, 2, 5 },
                       { 0, 0, 0, 6 } };
                      
        if (isUpperTriangularMatrix(mat))
            System.out.println("Yes");
        else
            System.out.println("No");
    }
}
  
/* This code is contributed by Sagar Shukla */

chevron_right


Python3

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python3 Program to check upper 
# triangular matrix.
  
# Function to check matrix 
# is in upper triangular
def isuppertriangular(M):
    for i in range(1, len(M)):
        for j in range(0, i):
            if(M[i][j] != 0): 
                    return False
    return True
      
# Driver function.
M = [[1,3,5,3],
    [0,4,6,2],
    [0,0,2,5],
    [0,0,0,6]]
  
if isuppertriangular(M):
    print ("Yes")
else:
    print ("No")
  
# This code is contributed by Anurag Rawat

chevron_right


C#

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# Program to check upper 
// triangular matrix.
using System;
  
public class GfG
{
    private static int N = 4;
  
    // Function to check matrix is in
    // upper triangular form or not.
    public static bool isUpperTriangularMatrix(int [,]mat)
    {
        for (int i = 1; i < N ; i++)
            for (int j = 0; j < i; j++)
                if (mat[i, j] != 0)
                    return false;
        return true;
    
      
    // Driver function
    public static void Main(){
        int [,]mat= { { 1, 3, 5, 3 },
                    { 0, 4, 6, 2 },
                    { 0, 0, 2, 5 },
                    { 0, 0, 0, 6 } };
                      
        if (isUpperTriangularMatrix(mat))
            Console.WriteLine("Yes");
        else
            Console.WriteLine("No");
    }
}
  
/* This code is contributed by vt_m */

chevron_right


PHP

filter_none

edit
close

play_arrow

link
brightness_4
code

<?php
// PHP Program to check upper 
// triangular matrix.
$N = 4;
  
// Function to check matrix is 
// in upper triangular form or
// not.
function isUpperTriangularMatrix($mat)
{
    global $N;
    for ($i = 1; $i < $N; $i++)
        for ($j = 0; $j < $i; $j++)
            if ($mat[$i][$j] != 0)
                return false;
    return true;
}
  
    // Driver Code
    $mat = array(array(1, 3, 5, 3),
                 array(0, 4, 6, 2) ,
                 array(0, 0, 2, 5),
                 array(0, 0, 0, 6));
                  
    if (isUpperTriangularMatrix($mat))
        echo "Yes";
    else
        echo"No";
  
// This code is contributed by anuj_67.
?>

chevron_right



Output:

Yes


My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.



Improved By : vt_m



Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.