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.
Python Program to check if matrix is lower triangular
Python3
# Python3 Program to check # lower triangular matrix.# Function to check matrix # is in lower triangulardef islowertriangular(M): for i in range(0, len(M)): for j in range(i + 1, len(M)): if(M[i][j] != 0): return False return True # Driver function.M = [[1,0,0,0], [1,4,0,0], [4,6,2,0], [0,4,7,6]]if islowertriangular(M): print ("Yes")else: print ("No") # This code is contributed by Anurag Rawat |
Output:
Yes
Time Complexity: O(n2), where n represents the number of rows and columns of the given matrix.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
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