Eigenvalues of Triangular Matrix

Problem

Return the eigenvalues of a square triangular matrix A (upper or lower triangular).

The eigenvalues are exactly the diagonal entries, returned in order as a list.

Hint

The characteristic polynomial of a triangular matrix is the product of (lambda - A[i][i]).

case 1

in: [[[2,5,7],[0,3,9],[0,0,4]]]

expected: [2,3,4]

case 2

in: [[[1,0,0],[2,3,0],[4,5,6]]]

expected: [1,3,6]

case 3

in: [[[5,0],[0,7]]]

expected: [5,7]

case 4

in: [[[1,0,0],[0,1,0],[0,0,1]]]

expected: [1,1,1]

Starter codePython

def triangular_eigenvalues(A):
    # Your code here
    pass

4 test cases · run your code against them in the editor