refactor 638

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_638.java

@@ -41,36 +41,40 @@
  You are not allowed to buy more items than you want, even if that would lower the overall price.
  */
 public class _638 {
-    /**reference: https://leetcode.com/articles/shopping-offers/#approach-1-using-recursion-accepted*/
-    public int shoppingOffers(List<Integer> price, List<List<Integer>> special, List<Integer> needs) {
-        return shopping(price, special, needs, 0);
-    }
-
-    public int shopping(List<Integer> price, List<List<Integer>> special, List<Integer> needs, int i) {
-        if (i == special.size()) {
-            return dot(needs, price);
+    public static class Solution1 {
+        /**
+         * reference: https://leetcode.com/articles/shopping-offers/#approach-1-using-recursion-accepted
+         */
+        public int shoppingOffers(List<Integer> price, List<List<Integer>> special, List<Integer> needs) {
+            return shopping(price, special, needs, 0);
         }
-        ArrayList<Integer> clone = new ArrayList(needs);
-        int j = 0;
-        for (j = 0; j < special.get(i).size() - 1; j++) {
-            int diff = clone.get(j) - special.get(i).get(j);
-            if (diff < 0) {
-                break;
+
+        public int shopping(List<Integer> price, List<List<Integer>> special, List<Integer> needs, int i) {
+            if (i == special.size()) {
+                return dot(needs, price);
+            }
+            ArrayList<Integer> clone = new ArrayList(needs);
+            int j = 0;
+            for (j = 0; j < special.get(i).size() - 1; j++) {
+                int diff = clone.get(j) - special.get(i).get(j);
+                if (diff < 0) {
+                    break;
+                }
+                clone.set(j, diff);
+            }
+            if (j == special.get(i).size() - 1) {
+                return Math.min(special.get(i).get(j) + shopping(price, special, clone, i), shopping(price, special, needs, i + 1));
+            } else {
+                return shopping(price, special, needs, i + 1);
             }
-            clone.set(j, diff);
-        }
-        if (j == special.get(i).size() - 1) {
-            return Math.min(special.get(i).get(j) + shopping(price, special, clone, i), shopping(price, special, needs, i + 1));
-        } else {
-            return shopping(price, special, needs, i + 1);
         }
-    }
 
-    public int dot(List<Integer> a, List<Integer> b) {
-        int sum = 0;
-        for (int i = 0; i < a.size(); i++) {
-            sum += a.get(i) * b.get(i);
+        public int dot(List<Integer> a, List<Integer> b) {
+            int sum = 0;
+            for (int i = 0; i < a.size(); i++) {
+                sum += a.get(i) * b.get(i);
+            }
+            return sum;
         }
-        return sum;
     }
 }