added field for writes used

Sorting/Sorter.java

@@ -13,6 +13,7 @@ abstract class Sorter {
     protected String sortType;
     protected Integer[] numbers;
     protected long comparisonsUsed = 0;
+    protected long wrtiesUsed=0;
 
     public Sorter(String st, String filename){
         sortType=st;
@@ -32,6 +33,7 @@ abstract class Sorter {
         int tmp = numbers[a];
         numbers[a] = numbers[b];
         numbers[b] = tmp;
+        wrtiesUsed+=2;
     }
 
     int compare(int a, int b){