leetcode 530. Minimum Absolute Difference in BST

leetcode 530. Minimum Absolute Difference in BST

#coding=utf-8
'''
Given a binary search tree with non-negative values,
find the minimum absolute difference between values of any two nodes.
Example:
Input:
  1
    \
    3
    /
  2
Output:
1
Explanation:
The minimum absolute difference is 1, which is the difference between 2 and 1 (or between 2 and 3).
'''

#其实简单的思路就是遍历这个二叉树的所有节点的值，然后进行排序，取相邻两个数差最小，最小的差就是所求的结果
# 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 getMinimumDifference(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        queue=[root];l=[root.val]
        while queue:
            node=queue.pop()#node等于退出的一个节点
            if node.left:
                queue.append(node.left)
                l.append(node.left.val)
            if node.right:
                queue.append(node.right)
                l.append(node.right.val)
        answer=[];sortedl=sorted(l)
        for i in range(1,len(sortedl)):
            answer.append(sortedl[i]-sortedl[i-1])
        return min(answer)

t=TreeNode(8)
t.left=TreeNode(3);t.right=TreeNode(10)

s=Solution()
print s.getMinimumDifference(t)