<doocs>1740.Find Distance in a Binary Tree_1.py
def dfs(root, v):
    if root is None:
        return -1
    if root.val == v:
        return 0
    left, right = dfs(root.left, v), dfs(root.right, v)
    if left == right == -1:
        return -1
    return 1 + max(left, right)
def sample_funcname ( var_1 , var_2 ) :
    if var_1 is None :
        return - 1
    if var_1.val == var_2 :
        return 0
    left , right = var_0 ( var_1.left , var_2 ) , var_0 ( var_1.right , var_2 )
    if left == right == - 1 :
        return - 1
    return 1 + max ( left , right )
