refactor 634

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_634.java

@@ -18,17 +18,19 @@
  n is in the range of [1, 106].
  */
 public class _634 {
-    /**
-     * reference: https://discuss.leetcode.com/topic/94442/java-5-lines-o-1-space-solution
-     * and https://leetcode.com/articles/find-derangements/#approach-5-using-formula-accepted
-     */
-    private static final int M = 1000000007;
+    public static class Solution1 {
+        /**
+         * reference: https://discuss.leetcode.com/topic/94442/java-5-lines-o-1-space-solution
+         * and https://leetcode.com/articles/find-derangements/#approach-5-using-formula-accepted
+         */
+        private static final int M = 1000000007;
 
-    public int findDerangement(int n) {
-        long ans = 1;
-        for (int i = 1; i <= n; i++) {
-            ans = (i * ans % M + (i % 2 == 0 ? 1 : -1)) % M;
+        public int findDerangement(int n) {
+            long ans = 1;
+            for (int i = 1; i <= n; i++) {
+                ans = (i * ans % M + (i % 2 == 0 ? 1 : -1)) % M;
+            }
+            return (int) ans;
         }
-        return (int) ans;
     }
 }