Simple Java Solution
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n *     int val;\n *     TreeNode left;\n *     TreeNode right;\n *     TreeNode() {}\n *     TreeNode(int val) { this.val = val; }\n *     TreeNode(int val, TreeNode left, TreeNode right) {\n *         this.val = val;\n *         this.left = left;\n *         this.right = right;\n *     }\n * }\n */\nclass Solution {\n    int sum = 0;\n    public int rangeSumBST(TreeNode root, int low, int high) {\n        if(root == null) {\n            return 0;\n        }\n        if(root.val >= low && root.val <= high) {\n            sum += root.val;\n        }\n        if(root.val > low) {\n            rangeSumBST(root.left, low, high);\n        }\n        if(root.val < high) {\n            rangeSumBST(root.right, low, high);\n        }\n        return sum;\n    }\n}\n```
['Tree', 'Depth-First Search', 'Binary Search Tree', 'Binary Tree', 'Java']