Python -在矩阵中生成相同值的链表

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def create_linked_list(matrix, value):
    if not matrix or not matrix[0]:
        return None

    rows, cols = len(matrix), len(matrix[0])
    visited = [[False] * cols for _ in range(rows)]
    head = None
    tail = None

    def dfs(x, y):
        nonlocal head, tail
        if x < 0 or x >= rows or y < 0 or y >= cols or visited[x][y] or matrix[x][y] != value:
            return

        visited[x][y] = True
        node = ListNode(matrix[x][y])
        if not head:
            head = node
            tail = node
        else:
            tail.next = node
            tail = node

        dfs(x + 1, y)
        dfs(x - 1, y)
        dfs(x, y + 1)
        dfs(x, y - 1)

    for i in range(rows):
        for j in range(cols):
            if matrix[i][j] == value and not visited[i][j]:
                dfs(i, j)

    return head

def print_linked_list(head):
    while head:
        print(head.val, end=" -> ")
        head = head.next
    print("None")

# 示例矩阵
matrix = [
    [1, 2, 2, 3],
    [4, 5, 5, 6],
    [7, 8, 8, 9]
]

# 生成值为2的链表
linked_list = create_linked_list(matrix, 2)
print_linked_list(linked_list)  # 输出: 2 -> 2 -> None

# 生成值为5的链表
linked_list = create_linked_list(matrix, 5)
print_linked_list(linked_list)  # 输出: 5 -> 5 -> None