[leetcode]@python 111. Minimum Depth of Binary Tree

题目链接

https://leetcode.com/problems/minimum-depth-of-binary-tree/

题目原文

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

题目大意

给出一棵树，求这棵树的最小深度（根节点到最近的叶节点的距离）

解题思路

递归求解

代码

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

class Solution(object):
    def minDepth(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        if root == None:
            return 0
        if root.left == None and root.right != None:
            return self.minDepth(root.right) + 1
        if root.left != None and root.right == None:
            return self.minDepth(root.left) + 1
        
        return min(self.minDepth(root.left), self.minDepth(root.right)) + 1