Javascript Program to check if matrix is upper triangular

Last Updated : 10 Jun, 2022

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.

Javascript

<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

Time Complexity: O(n²), where n represents the number of rows and columns of the matrix.
Auxiliary Space: O(1), no extra space is required, so it is a constant.

Please refer complete article on Program to check if matrix is upper triangular for more details!

Suggest improvement

Javascript Program for Counting sets of 1s and 0s in a binary matrix

Java Program to Print a given matrix in reverse spiral form

Share your thoughts in the comments