4/10/2017 - 3:24 PM


# 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
        elif root.left == None:
            return self.minDepth(root.right)+1
        elif root.right == None:
            return self.minDepth(root.left)+1
            return min(self.minDepth(root.left)+1, self.minDepth(root.right)+1)

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.