Program to check if matrix is upper triangular - GeeksforGeeks

26 Apr, 2021
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++
Java
Python3
C#
PHP
Javascript
// Program to check upper triangular matrix.#include <bits/stdc++.h>#define N 4using 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;}
// 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 */
# Python3 Program to check upper# triangular matrix. # Function to check matrix# is in upper triangulardef 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
// 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 */
<?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.?>
<script>// Java script  Program to check upper// triangular matrix.let  N = 4;     // Function to check matrix is in    // upper triangular form or not.    function isUpperTriangularMatrix(mat)    {        for (let i = 1; i < N ; i++)            for (let j = 0; j < i; j++)                if (mat[i][j] != 0)                    return false;        return true;    }         // driver function             let mat= [[1, 3, 5, 3 ],                    [ 0, 4, 6, 2 ],                    [ 0, 0, 2, 5 ],                    [ 0, 0, 0, 6 ]];                             if (isUpperTriangularMatrix(mat))            document.write("Yes");        else            document.write("No");              // contributed by sravan kumar</script>
Output:  
Yes
 
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sravankumar8128
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