力扣-二叉树-669 修剪二叉搜索树

思路

和之前的二叉搜索树类似，再寻找不符合条件的节点过程中，用上一层的左或者右接住下一层return回来的根节点

代码

class Solution {
public:TreeNode* trimBST(TreeNode* root, int low, int high) {if(root == nullptr) return nullptr;if(root->val < low){return trimBST(root->right, low, high);}else if(root->val > high){return trimBST(root->left, low, high);}else{root->left = trimBST(root->left, low, high);root->right = trimBST(root->right, low, high);}return root;}
};