Title description:
Given the root node root of the binary search tree, the return value is the sum of the values of all nodes in the range [low, high].
prompt:
- The number of nodes in the tree is in the range [1, 2 * 104]
- 1 <= Node.val <= 105
- 1 <= low <= high <= 105
- All Node.vals are different from each other
Example 1:
Input: root = [10,5,15,3,7,null,18], low = 7, high = 15
Output: 32
Example 2:
Input: root = [10,5,15,3,7,13,18,1,null,6], low = 6, high = 10
Output: 23
code show as below:
/**
* Definition for a binary tree node.
* public 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 {
public static int rangeSumBST(TreeNode root, int low, int high) {
ArrayList<Integer> list = new ArrayList<>();
mid(root, list);
int ans = 0;
for (Integer k : list) {
if (k >= low && k <= high) {
ans += k;
}
}
return ans;
}
public static void mid(TreeNode root, ArrayList<Integer> list) {
if (root == null) {
return;
}
mid(root.left, list);
list.add(root.val);
mid(root.right, list);
}
}
Results of the:
