leetcode中等669修剪二叉搜索树

Posted 2021-11-24 qq_40707462

class Solution {
    public TreeNode trimBST(TreeNode root, int low, int high) {
        if(root==null) return null;
        if(root.val<low) {
            TreeNode rnode=trimBST(root.right,low,high);
            return rnode;
        }
        if(root.val>high){
            TreeNode lnode=trimBST(root.left,low,high);
            return lnode;
        }
        root.left=trimBST(root.left,low,high);
        root.right=trimBST(root.right,low,high);
        return root;
    }
}