Given the root node of a binary search tree, return the sum of values of all nodes with value between L and R (inclusive).
The binary search tree is guaranteed to have unique values.
Example 1:
Input: root = [10,5,15,3,7,null,18], L = 7, R = 15 Output: 32 Example 2:
Input: root = [10,5,15,3,7,13,18,1,null,6], L = 6, R = 10 Output: 23
Note:
The number of nodes in the tree is at most 10000. The final answer is guaranteed to be less than 2^31.
/**
* Definition for a binary tree node.
* public class TreeNode {
* public int val;
* public TreeNode left;
* public TreeNode right;
* public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
public class Solution {
public int RangeSumBST(TreeNode root, int L, int R) {
if(root==null){
return 0;
}
if(L>root.val){
return RangeSumBST(root.right,L,R);
}
if(R<root.val){
return RangeSumBST(root.left,L,R);
}
return root.val+RangeSumBST(root.right,L,R)+RangeSumBST(root.left,L,R);
}
}Time Complexity: O(n)
Space Complexity: O(height)
