LeetCode Solutions
669. Trim a Binary Search Tree
Time: $O(n)$ Space: $O(h)$
class Solution {
public:
TreeNode* trimBST(TreeNode* root, int L, int R) {
if (root == nullptr)
return nullptr;
if (root->val < L)
return trimBST(root->right, L, R);
if (root->val > R)
return trimBST(root->left, L, R);
root->left = trimBST(root->left, L, R);
root->right = trimBST(root->right, L, R);
return root;
}
};
class Solution {
public TreeNode trimBST(TreeNode root, int low, int high) {
if (root == null)
return null;
if (root.val < low)
return trimBST(root.right, low, high);
if (root.val > high)
return trimBST(root.left, low, high);
root.left = trimBST(root.left, low, high);
root.right = trimBST(root.right, low, high);
return root;
}
}