added code to count write operations used

Sorting/MergeSorter.java

@@ -32,30 +32,37 @@ public class MergeSorter extends Sorter{
         int[] right=new int[sizeRight];
         for(int i=0;i<sizeLeft;i++){
             left[i]=numbers[leftIndex+i];
+            writesUsed++;
         }
         for(int i=0;i<sizeRight;i++){
             right[i]=numbers[middleIndex+1+i];
+            writesUsed++;
         }
         int i=0, j=0;//indices of left and right array
         int k=leftIndex;//index of numbers array
         while(i<sizeLeft&&j<sizeRight){
             if(compare(left[i],right[j])<1){
                 numbers[k]=left[i];
+                writesUsed++;
+
                 i++;
             }
             else{
                 numbers[k]=right[j];
+                writesUsed++;
                 j++;
             }
             k++;
         }
         while(i<sizeLeft){
             numbers[k]=left[i];
+            writesUsed++;
             i++;
             k++;
         }
         while(j<sizeRight){
             numbers[k]=right[j];
+            writesUsed++;
             j++;
             k++;
         }