题目:给一颗BST,找两个节点最小绝对值的差
思路:遍历一下,再扫一遍就行。。。。。
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { ArrayList<Integer> nodes = new ArrayList<Integer>(); public int getMinimumDifference(TreeNode root) { getNodes(root); int res = Integer.MAX_VALUE; for(int i = 1;i < nodes.size();i++){ Integer resid = nodes.get(i) - nodes.get(i-1); if(resid < res) res = resid; } return res; } public void getNodes(TreeNode root){ if(root != null){ getNodes(root.left); nodes.add(root.val); getNodes(root.right); } } }