111. Minimum Depth of Binary Tree

Original title:

111. Minimum Depth of Binary Tree

Read the question:

To find the minimum depth, which is similar to the maximum depth of the tree, it is only necessary to note that when the Zuozi or right subtree is empty, the minimum depth is not 0, but depends on the minimum depth of the nonempty tree.

# 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< C13/>:rtype:int "" "
        if not root:
            return 0
        lengthl = self.mindepth (root.left)
        lengthr = Self.mindepth (root.right)
        if not LENGTHL:
            return lengthr + 1
        if not lengthr:
            return LENGTHL + 1
        return min (LENGTHR,LENGTHL) + 1