LeetCode:Minimum Depth of Binary Tree

最新推荐文章于 2020-02-19 02:21:51 发布

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本文介绍了一种求解二叉树最小深度的算法实现，该算法递归地计算左子树和右子树的最小深度，并返回较短路径加一的结果。适用于计算机科学与数据结构学习。

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.

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

class Solution:
    # @param root, a tree node
    # @return an integer
    def minDepth(self, root):
        if (root==None):
            return 0
        elif (root.left==None and root.right==None):
            return 1 #和最深不一样，因为要保证最短的也是从叶子节点开始的
        else:
            minDepthLeft=self.minDepth(root.left);
            minDepthRight=self.minDepth(root.right);
            if minDepthLeft==0:<span style="font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;">#和最深不一样，因为要保证最短的也是从叶子节点开始的</span>
                return minDepthRight+1
            if minDepthRight==0:
                return minDepthLeft+1
            if (minDepthLeft>minDepthRight):
                return minDepthRight+1
            else:
                return minDepthLeft+1