<p>You are given two integers <code>m</code> and <code>n</code>, which represent the dimensions of a matrix.</p>

<p>You are also given the <code>head</code> of a linked list of integers.</p>

<p>Generate an <code>m x n</code> matrix that contains the integers in the linked list presented in <strong>spiral</strong> order <strong>(clockwise)</strong>, starting from the <strong>top-left</strong> of the matrix. If there are remaining empty spaces, fill them with <code>-1</code>.</p>

<p>Return <em>the generated matrix</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/05/09/ex1new.jpg" style="width: 240px; height: 150px;" />
<pre>
<strong>Input:</strong> m = 3, n = 5, head = [3,0,2,6,8,1,7,9,4,2,5,5,0]
<strong>Output:</strong> [[3,0,2,6,8],[5,0,-1,-1,1],[5,2,4,9,7]]
<strong>Explanation:</strong> The diagram above shows how the values are printed in the matrix.
Note that the remaining spaces in the matrix are filled with -1.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/05/11/ex2.jpg" style="width: 221px; height: 60px;" />
<pre>
<strong>Input:</strong> m = 1, n = 4, head = [0,1,2]
<strong>Output:</strong> [[0,1,2,-1]]
<strong>Explanation:</strong> The diagram above shows how the values are printed from left to right in the matrix.
The last space in the matrix is set to -1.</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= m, n &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= m * n &lt;= 10<sup>5</sup></code></li>
	<li>The number of nodes in the list is in the range <code>[1, m * n]</code>.</li>
	<li><code>0 &lt;= Node.val &lt;= 1000</code></li>
</ul>

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def spiralMatrix(self, m: int, n: int, head: Optional[ListNode]) -> List[List[int]]:

        # Generate a matrix, fill with -1 to handle the case where the linked list doesn't fill the matrix
        matrix = []
        for _ in range(m):
            matrix.append([-1] * n)
        
        # Start matrix at 0,0
        x, y = 0, 0
        print(x, y)
        # Keep track of if moving left to right and up/down
        left_to_right = True
        top_to_bottom = True
        moving_horizontally = True

        # Iterate through the linked list
        ptr = head
        while ptr:
            # Set the current matrix value to the linked list value
            matrix[y][x] = ptr.val
            
            # Advance the linked list pointer
            ptr = ptr.next

            # Advance the matrix coordinates
            if moving_horizontally:
                x += 1 if left_to_right else -1

                # if you hit the end (off the grid or a non--1 value), change directions
                if x == n or x == -1 or matrix[y][x] != -1:
                    x -= 1 if left_to_right else -1
                    left_to_right = not left_to_right
                    moving_horizontally = not moving_horizontally
                    y += 1 if top_to_bottom else -1
            else:
                y += 1 if top_to_bottom else -1
                
                if y == m or matrix[y][x] != -1:
                    y -= 1 if top_to_bottom else -1
                    top_to_bottom = not top_to_bottom
                    moving_horizontally = not moving_horizontally
                    x += 1 if left_to_right else -1
            print(x, y)
        return matrix




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