Determinant by Expansion along a Row

Problem

Compute the determinant of a square matrix A by cofactor expansion along the given row index:

det(A) = sum_j (-1)^(row + j) * A[row][j] * det(minor(row, j))

Use recursive expansion of the minors.

Hint

The answer is the same for every row; only the amount of arithmetic changes.

case 1

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

expected: -2

case 2

in: [[[1,2],[3,4]],1]

expected: -2

case 3

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

expected: 41

case 4

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

expected: 41

Starter codePython

def det_expand_row(A, row):
    # Your code here
    pass

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