refactor 147

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_147.java

@@ -6,33 +6,53 @@
 import java.util.List;
 
 /**
+ * 147. Insertion Sort List
+ *
  * Sort a linked list using insertion sort.
+ *
+ * Algorithm of Insertion Sort:
+ *
+ *     Insertion sort iterates, consuming one input element each repetition, and growing a sorted output list.
+ *     At each iteration, insertion sort removes one element from the input data, finds the location it belongs within the sorted list, and inserts it there.
+ *     It repeats until no input elements remain.
+ *
+ *
+ * Example 1:
+ *
+ * Input: 4->2->1->3
+ * Output: 1->2->3->4
+ *
+ * Example 2:
+ *
+ * Input: -1->5->3->4->0
+ * Output: -1->0->3->4->5
  */
 public class _147 {
 
+  public static class Solution1 {
     public ListNode insertionSortList(ListNode head) {
-        ListNode temp = head;
-        List<Integer> list = new ArrayList<Integer>();
-        while (temp != null) {
-            list.add(temp.val);
-            temp = temp.next;
+      ListNode temp = head;
+      List<Integer> list = new ArrayList<>();
+      while (temp != null) {
+        list.add(temp.val);
+        temp = temp.next;
+      }
+      Integer[] nums = list.toArray(new Integer[list.size()]);
+      for (int i = 1; i < list.size(); i++) {
+        for (int j = i - 1; j >= 0; j--) {
+          if (nums[j] > nums[j + 1]) {
+            int tempNum = nums[j];
+            nums[j] = nums[j + 1];
+            nums[j + 1] = tempNum;
+          }
         }
-        Integer[] nums = list.toArray(new Integer[list.size()]);
-        for (int i = 1; i < list.size(); i++) {
-            for (int j = i - 1; j >= 0; j--) {
-                if (nums[j] > nums[j + 1]) {
-                    int tempNum = nums[j];
-                    nums[j] = nums[j + 1];
-                    nums[j + 1] = tempNum;
-                }
-            }
-        }
-        ListNode newHead = head;
-        for (int i = 0; i < nums.length; i++) {
-            newHead.val = nums[i];
-            newHead = newHead.next;
-        }
-        return head;
+      }
+      ListNode newHead = head;
+      for (int i = 0; i < nums.length; i++) {
+        newHead.val = nums[i];
+        newHead = newHead.next;
+      }
+      return head;
     }
-
+  }
 }