Update Java Interface

Author: Psingh12354

Java Interface

@@ -37,3 +37,15 @@ class Solution{
     }
 }
 
+//or
+class MyCalculator implements AdvancedArithmetic{
+    int sum=0;
+    public int divisor_sum(int n){
+        for(int i=1;i<=n/2;i++){
+            if(n%i==0){
+                sum+=i;
+            }
+        }
+        return sum+n;
+    }
+}