Leetcode 104 & 111. Minimum & Maximum Depth of Binary Tree

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def maxDepth(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        if not root:
            return 0
        l=self.maxDepth(root.left)+1
        r=self.maxDepth(root.right)+1
        return max(l,r)

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def minDepth(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        d=[]
        if not root:
            return 0
        def minD(root,num):
            if not root:
                return
            if not root.left and not root.right:
                d.append(num)
            else:
                minD(root.left,num+1)
                minD(root.right,num+1)
        minD(root,1)
        return min(d)