from typing import List

# Problem #8 [Easy]
# Good morning! Here's your coding interview problem for today.

# This problem was asked by Google.

# A unival tree (which stands for "universal value") is a tree
# where all nodes under it have the same value.

# Given the root to a binary tree, count the number of unival subtrees.

# For example, the following tree has 5 unival subtrees:

#    0
#   / \
#  1   0
#     / \
#    1   0
#   / \
#  1   1

tests = None
solver = None
