add py3/node soln

0669_trim-a-binary-search-tree/nodejs/solution.js

@@ -0,0 +1,29 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number} low
+ * @param {number} high
+ * @return {TreeNode}
+ */
+ function trimBST(root, low, high) {
+    if (!root) {
+        return null;
+    }
+    
+    if (root.val < low) {
+        return trimBST(root.right, low, high);
+    } else if (root.val > high) {
+        return trimBST(root.left, low, high);
+    } else {
+        root.left = trimBST(root.left, low, high);
+        root.right = trimBST(root.right, low, high);
+        return root;
+    }
+};