Given a square matrix and the task is to check the matrix is in lower triangular form or not. A square matrix is called lower triangular if all the entries above the main diagonal are zero.
Examples:
Input : mat[4][4] = {{1, 0, 0, 0}, {1, 4, 0, 0}, {4, 6, 2, 0}, {0, 4, 7, 6}}; Output : Matrix is in lower triangular form. Input : mat[4][4] = {{1, 0, 0, 0}, {4, 3, 0, 1}, {7, 9, 2, 0}, {8, 5, 3, 6}}; Output : Matrix is not in lower triangular form.
Java
// Java Program to check for // a lower triangular matrix. import java.io.*; class Lower_triangular { int N = 4 ; // Function to check matrix is // in lower triangular form or not. boolean isLowerTriangularMatrix( int mat[][]) { for ( int i = 0 ; i < N; i++) for ( int j = i + 1 ; j < N; j++) if (mat[i][j] != 0 ) return false ; return true ; } // Driver function. public static void main(String args[]) { Lower_triangular ob = new Lower_triangular(); int mat[][] = { { 1 , 0 , 0 , 0 }, { 1 , 4 , 0 , 0 }, { 4 , 6 , 2 , 0 }, { 0 , 4 , 7 , 6 } }; // Function call if (ob.isLowerTriangularMatrix(mat)) System.out.println( "Yes" ); else System.out.println( "No" ); } } // This code is contributed by Anshika Goyal. |
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.
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