9.Path Sum

Description:

　　Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

解题思路：

　　碰到树的问题我会优先考虑递归。这题使用递归可以很快解出。先考虑初始条件，如果root为空，直接判定为false。若该树只有一个根结点，且结点值等于sum，返回true。设置好这两个入口条件后，即可递归使用函数求解。

程序如下：

时间： 2024-08-27 13:52:01

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