Spiral Matrix II

1def generateMatrix(n: int) -> List[List[int]]:
2    matrix = [[0] * n for _ in range(n)]
3    top, bottom = 0, n - 1
4    left, right = 0, n - 1
5    num = 1
6    
7    while top <= bottom and left <= right:
8        # Fill Top Row
9        for i in range(left, right + 1):
10            matrix[top][i] = num
11            num += 1
12        top += 1
13        
14        # Fill Right Col
15        for i in range(top, bottom + 1):
16            matrix[i][right] = num
17            num += 1
18        right -= 1
19        
20        if top <= bottom:
21            # Fill Bottom Row
22            for i in range(right, left - 1, -1):
23                matrix[bottom][i] = num
24                num += 1
25            bottom -= 1
26            
27        if left <= right:
28            # Fill Left Col
29            for i in range(bottom, top - 1, -1):
30                matrix[i][left] = num
31                num += 1
32            left += 1
33            
34    return matrix