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)