Spiral Matrix Generation

Problem

Generate an n by n matrix filled with the numbers 1 to n squared in clockwise spiral order starting at the top-left corner.

Maintain top, bottom, left and right boundaries, walking each side and shrinking that boundary after every pass. Return an empty list for n <= 0.

Hint

After each side, move its boundary inward; guard the last row and column when the center is reached.

case 1

in: [1]

expected: [[1]]

case 2

in: [2]

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

case 3

in: [3]

expected: [[1,2,3],[8,9,4],[7,6,5]]

case 4

in: [0]

expected: []

Starter codePython

def generate_spiral_matrix(n):
    # Your code here
    pass

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