<doocs>1372.Longest ZigZag Path in a Binary Tree_1.py
def dfs(root, l, r):
    if root is None:
        return
    nonlocal ans
    ans = max(ans, l, r)
    dfs(root.left, r + 1, 0)
    dfs(root.right, 0, l + 1)
def sample_funcname ( var_1 , var_2 , var_3 ) :
    if var_1 is None :
        return
    nonlocal var_5
    var_5 = max ( var_5 , var_2 , var_3 )
    var_0 ( var_1.left , var_3 + 1 , 0 )
    var_0 ( var_1.right , 0 , var_2 + 1 )
