updates

Author: fanzipei

226_invert_binary_tree.scala

@@ -0,0 +1,11 @@
+object Solution {
+    def invertTree(root: TreeNode): TreeNode = {
+        if (root == null) null
+        else {
+            val tmp = invertTree(root.left)
+            root.left = invertTree(root.right)
+            root.right = tmp
+            root
+        }
+    }
+}

638_shopping_offers.scala

@@ -0,0 +1,6 @@
+object Solution {
+    def shoppingOffers(price: List[Int], special: List[List[Int]], needs: List[Int]): Int = {
+        val special_filtered = special.filter(x => (x.init zip needs).map(y => y._1 <= y._2).reduce(_ && _))
+        (special_filtered.map(x => x.last + shoppingOffers(price, special_filtered, (needs zip x.init).map(y => y._1 - y._2))) ++ List((price zip needs).map(x => x._1 * x._2).reduce(_ + _))).reduce(Math.min)
+    }
+}