refactor 413

fishercoder1534 · fishercoder1534 · commit 63da9907a500 · 2019-03-14T07:21:54.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_413.java b/src/main/java/com/fishercoder/solutions/_413.java
@@ -1,12 +1,16 @@
 package com.fishercoder.solutions;
 
-/**A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.
+/**
+ * 413. Arithmetic Slices
+ *
+ * A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.
 
  For example, these are arithmetic sequence:
 
  1, 3, 5, 7, 9
  7, 7, 7, 7
  3, -1, -5, -9
+
  The following sequence is not arithmetic.
 
  1, 1, 2, 5, 7
@@ -18,40 +22,42 @@ A slice (P, Q) of array A is called arithmetic if the sequence:
 
  The function should return the number of arithmetic slices in the array A.
 
-
  Example:
 
  A = [1, 2, 3, 4]
 
- return: 3, for 3 arithmetic slices in A: [1, 2, 3], [2, 3, 4] and [1, 2, 3, 4] itself.*/
+ return: 3, for 3 arithmetic slices in A: [1, 2, 3], [2, 3, 4] and [1, 2, 3, 4] itself.
+ */
 public class _413 {
 
-    //copied this solution: https://discuss.leetcode.com/topic/62884/2ms-java-o-n-time-o-1-space-solution
-    public int numberOfArithmeticSlices(int[] A) {
-        int sum = 0;
-        int len = 2;
-        for (int i = 2; i < A.length; i++) {
-            if (A[i] - A[i - 1] == A[i - 1] - A[i - 2]) {
-                len++;
-            } else {
-                if (len > 2) {
-                    sum += calculateSlices(len);
+    public static class Solution1 {
+        //credit: https://discuss.leetcode.com/topic/62884/2ms-java-o-n-time-o-1-space-solution
+        public int numberOfArithmeticSlices(int[] A) {
+            int sum = 0;
+            int len = 2;
+            for (int i = 2; i < A.length; i++) {
+                if (A[i] - A[i - 1] == A[i - 1] - A[i - 2]) {
+                    len++;
+                } else {
+                    if (len > 2) {
+                        sum += calculateSlices(len);
+                    }
+                    len = 2;//reset it to 2
                 }
-                len = 2;//reset it to 2
             }
+            if (len > 2) {
+                sum += calculateSlices(len);
+            }
+            return sum;
         }
-        if (len > 2) {
-            sum += calculateSlices(len);
-        }
-        return sum;
-    }
 
-    int calculateSlices(int len) {
-        return (len - 1) * (len - 2) / 2;
+        int calculateSlices(int len) {
+            return (len - 1) * (len - 2) / 2;
+        }
     }
 
     class Solution2 {
-        //a more clear solution: https://discuss.leetcode.com/topic/63302/simple-java-solution-9-lines-2ms
+        //credit: https://discuss.leetcode.com/topic/63302/simple-java-solution-9-lines-2ms
         public int numberOfArithmeticSlices(int[] A) {
             int sum = 0;
             int curr = 0;
