refactor 241

fishercoder1534 · fishercoder1534 · commit 7b5bd291d8ff · 2018-10-16T07:29:09.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_241.java b/src/main/java/com/fishercoder/solutions/_241.java
@@ -29,49 +29,52 @@
 
  */
 public class _241 {
-    /**Time:  O(n * 4^n / n^(3/2)) ~= n * Catalan numbers = n * (C(2n, n) - C(2n, n - 1)),
-                                     due to the size of the results is Catalan numbers,
-                                     and every way of evaluation is the length of the string,
-                                     so the time complexity is at most n * Catalan numbers.
-      Space: O(n * 4^n / n^(3/2)), the cache size of lookup is at most n * Catalan numbers.*/
+    public static class Solution1 {
+        /**Time:  O(n * 4^n / n^(3/2)) ~= n * Catalan numbers = n * (C(2n, n) - C(2n, n - 1)),
+         due to the size of the results is Catalan numbers,
+         and every way of evaluation is the length of the string,
+         so the time complexity is at most n * Catalan numbers.
+         Space: O(n * 4^n / n^(3/2)), the cache size of lookup is at most n * Catalan numbers.*/
 
-    /**Credit: https://discuss.leetcode.com/topic/19901/a-recursive-java-solution-284-ms*/
-    public List<Integer> diffWaysToCompute(String input) {
-        List<Integer> answer = new LinkedList<>();
-        int len = input.length();
-        for (int i = 0; i < len; i++) {
-            if (input.charAt(i) == '+'
-                    || input.charAt(i) == '-'
-                    || input.charAt(i) == '*') {
-                String part1 = input.substring(0, i);
-                String part2 = input.substring(i + 1);
-                List<Integer> answer1 = diffWaysToCompute(part1);
-                List<Integer> answer2 = diffWaysToCompute(part2);
-                for (int a1 : answer1) {
-                    for (int a2 : answer2) {
-                        int result = 0;
-                        switch (input.charAt(i)) {
-                            case '+':
-                                result = a1 + a2;
-                                break;
-                            case '-':
-                                result = a1 - a2;
-                                break;
-                            case '*':
-                                result = a1 * a2;
-                                break;
-                            default:
-                                break;
+        /**
+         * Credit: https://discuss.leetcode.com/topic/19901/a-recursive-java-solution-284-ms
+         */
+        public List<Integer> diffWaysToCompute(String input) {
+            List<Integer> answer = new LinkedList<>();
+            int len = input.length();
+            for (int i = 0; i < len; i++) {
+                if (input.charAt(i) == '+'
+                        || input.charAt(i) == '-'
+                        || input.charAt(i) == '*') {
+                    String part1 = input.substring(0, i);
+                    String part2 = input.substring(i + 1);
+                    List<Integer> answer1 = diffWaysToCompute(part1);
+                    List<Integer> answer2 = diffWaysToCompute(part2);
+                    for (int a1 : answer1) {
+                        for (int a2 : answer2) {
+                            int result = 0;
+                            switch (input.charAt(i)) {
+                                case '+':
+                                    result = a1 + a2;
+                                    break;
+                                case '-':
+                                    result = a1 - a2;
+                                    break;
+                                case '*':
+                                    result = a1 * a2;
+                                    break;
+                                default:
+                                    break;
+                            }
+                            answer.add(result);
                         }
-                        answer.add(result);
                     }
                 }
             }
+            if (answer.size() == 0) {
+                answer.add(Integer.valueOf(input));
+            }
+            return answer;
         }
-        if (answer.size() == 0) {
-            answer.add(Integer.valueOf(input));
-        }
-        return answer;
     }
-
 }
