Find Value in a Binary Tree

A list that represents a Binary Tree is in the following form:

binary_tree = [val, lst_left, lst_right]

When lst_left is the left side of the tree and lst_right is the right side of the tree.

To illustrate:

list1 = [3, [ 8, [ 5, None, None], None], [ 7, None, None]]

# list1 represents the following Binary Tree:

                    3
                   / \
                  8   7
                 /\   /\
                5  N N  N
               /\
               N N

# While N represents None.

Create a function that takes a list that represent a Binary Tree and a value and return True if the value is in the tree and, False otherwise.

Examples

is_val_in_tree(list1, 5) ➞ True

is_val_in_tree(list1, 9) ➞ False

is_val_in_tree(lst2, 51) ➞ False

Notes

The tree will contain integers only and will be presented by a list in the specified format.