1. 题目
2. 思路
(1) 递归
- 利用递归实现中序遍历，返回相邻结点差值的最小值即可。
3. 代码
public class Test {
public static void main(String[] args) {
}
}
class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode() {
}
TreeNode(int val) {
this.val = val;
}
TreeNode(int val, TreeNode left, TreeNode right) {
this.val = val;
this.left = left;
this.right = right;
}
}
class Solution {
private int pre;
private int differ;
public int getMinimumDifference(TreeNode root) {
pre = -(int) 1e4;
differ = Integer.MAX_VALUE;
inorder(root);
return differ;
}
private void inorder(TreeNode root) {
if (root == null) {
return;
}
inorder(root.left);
differ = Math.min(differ, root.val - pre);
pre = root.val;
inorder(root.right);
}
}