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.
Java
// 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 */ |
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!
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