Given a binary search tree with positive values, find the minimum absolute difference between values of any two nodes.
Sample Input:
root =[18, 7, 25, 2, 13, None, 34, None, None, 10, 16, 29]
Sample Output:
2
In the given sample BST tree, the minimum difference is between node value 16 and 18, which is 2.
数据结构和算法：初级练习题 #40 – 二叉搜索树最小差值
给定一颗二叉搜索树，找出任何两个结点之间的最小差值。
输入样例：
root =[18, 7, 25, 2, 13, None, 34, None, None, 10, 16, 29]
输出样例：
2
在上面的输入样例中，结点16和18之间的差值2是整个二叉搜索树所有结点的最小差值。
Python Solution
