编程求从二叉树根结点到到指定结点p之间的路径

以下是Python代码实现：

class TreeNode:
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None

def find_path(root, p):
    if not root:
        return []
    if root.val == p.val:
        return [root.val]
    left_path = find_path(root.left, p)
    if left_path:
        return [root.val] + left_path
    right_path = find_path(root.right, p)
    if right_path:
        return [root.val] + right_path
    return []

# 测试代码
root = TreeNode(1)
node2 = TreeNode(2)
node3 = TreeNode(3)
node4 = TreeNode(4)
node5 = TreeNode(5)
node6 = TreeNode(6)
node7 = TreeNode(7)

root.left = node2
root.right = node3
node2.left = node4
node2.right = node5
node3.left = node6
node3.right = node7

p = node5
path = find_path(root, p)
print(path)

输出：

[1, 2, 5]

其中，`find_path`函数的参数为二叉树的根节点`root`和指定节点`p`，返回值为从根节点到指定节点的路径。如果找不到指定节点，则返回空列表。