solve problem Range Sum Of Bst

Author: P-ppc

README.md

@@ -311,6 +311,7 @@ All solutions will be accepted!
 |8|[String To Integer Atoi](https://leetcode-cn.com/problems/string-to-integer-atoi/description/)|[java/py/js](./algorithms/StringToIntegerAtoi)|Medium|
 |299|[Bulls And Cows](https://leetcode-cn.com/problems/bulls-and-cows/description/)|[java/py/js](./algorithms/BullsAndCows)|Medium|
 |394|[Decode String](https://leetcode-cn.com/problems/decode-string/description/)|[java/py/js](./algorithms/DecodeString)|Medium|
+|938|[Range Sum Of Bst](https://leetcode-cn.com/problems/range-sum-of-bst/description/)|[java/py/js](./algorithms/RangeSumOfBst)|Medium|
 
 # Database
 |#|Title|Solution|Difficulty|

algorithms/RangeSumOfBst/README.md

@@ -0,0 +1,2 @@
+# Range Sum Of Bst
+We can solve this problem by recursive

algorithms/RangeSumOfBst/Solution.java

@@ -0,0 +1,21 @@
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+    public int rangeSumBST(TreeNode root, int L, int R) {
+        if (root == null)
+            return 0;
+        else if (root.val < L)
+            return rangeSumBST(root.right, L, R);
+        else if (root.val > R)
+            return rangeSumBST(root.left, L, R);
+        else
+            return root.val + rangeSumBST(root.right, L, R) + rangeSumBST(root.left, L, R);
+    }
+}

algorithms/RangeSumOfBst/solution.js

@@ -0,0 +1,23 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number} L
+ * @param {number} R
+ * @return {number}
+ */
+var rangeSumBST = function(root, L, R) {
+    if (!root)
+        return 0
+    else if (root.val < L)
+        return rangeSumBST(root.right, L, R)
+    else if (root.val > R)
+        return rangeSumBST(root.left, L, R)
+    else
+        return root.val + rangeSumBST(root.right, L, R) + rangeSumBST(root.left, L, R)
+};

algorithms/RangeSumOfBst/solution.py

@@ -0,0 +1,23 @@
+# Definition for a binary tree node.
+# class TreeNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution(object):
+    def rangeSumBST(self, root, L, R):
+        """
+        :type root: TreeNode
+        :type L: int
+        :type R: int
+        :rtype: int
+        """
+        if not root:
+            return 0
+        elif root.val < L:
+            return self.rangeSumBST(root.right, L, R)
+        elif root.val > R:
+            return self.rangeSumBST(root.left, L, R)
+        else:
+            return root.val + self.rangeSumBST(root.left, L, R) + self.rangeSumBST(root.right, L, R)