Where in this class would you increment compCount and swapCount? I'm close, but my final answer is off (this is the unmodified code).

import java.util.Random; public class MergeSort { private int[] data; // array of values private static final Random generator = new Random(); private int swapCount; private int compCount; // create array of given size and fill with random integers

public MergeSort( int size ) { data = new int[ size ]; // create space for array // fill array with random ints in range 10-99 for ( int i = 0; i < data.length-1; i++ ) data[ i ] = 10 + generator.nextInt(99 ); swapCount=0; compCount=0; } // end MergeSort constructor

// calls recursive split method to begin merge sorting public void sort() { sortArray( 0, data.length - 1 ); // split entire array System.out.println("Number of Comparisons in MergeSort " + compCount); System.out.println("Number of Swaps in MergeSort " + swapCount); } // end method sort // splits array, sorts subarrays and merges subarrays into sorted array private void sortArray( int low, int high ) { compCount=0; swapCount=0; // test base case; size of array equals 1 if ( ( high - low ) >= 1 ) // if not base case { int middle1 = ( low + high ) / 2; // calculate middle of array int middle2 = middle1 + 1; // calculate next element over // output split step //System.out.println( "split: " + subarray( low, high ) ); //System.out.println( " " + subarray( low, middle1 ) ); //System.out.println( " " + subarray( middle2, high ) ); //System.out.println(); // split array in half; sort each half (recursive calls) sortArray( low, middle1 ); // first half of array sortArray( middle2, high ); // second half of array // merge two sorted arrays after split calls return merge ( low, middle1, middle2, high ); } // end if } // end method sortArray

// merge two sorted subarrays into one sorted subarray private void merge( int left, int middle1, int middle2, int right ) { int leftIndex = left; // index into left subarray int rightIndex = middle2; // index into right subarray int combinedIndex = left; // index into temporary working array int[] combined = new int[ data.length ]; // working array // output two subarrays before merging //System.out.println( "merge: " + subarray( left, middle1 ) ); //System.out.println( " " + subarray( middle2, right ) ); // merge arrays until reaching end of either while ( leftIndex <= middle1 && rightIndex <= right ) { // place smaller of two current elements into result // and move to next space in arrays if ( data[ leftIndex ] <= data[ rightIndex ] ) combined[ combinedIndex++ ] = data[ leftIndex++ ]; else combined[ combinedIndex++ ] = data[ rightIndex++ ]; } // end while // if left array is empty if ( leftIndex == middle2 ) // copy in rest of right array while ( rightIndex <= right ) combined[ combinedIndex++ ] = data[ rightIndex++ ]; else // right array is empty // copy in rest of left array while ( leftIndex <= middle1 ) combined[ combinedIndex++ ] = data[ leftIndex++ ]; // copy values back into original array for ( int i = left; i <= right; i++ ) data[ i ] = combined[ i ]; // output merged array //System.out.println( " " + subarray( left, right ) ); //System.out.println(); } // end method merge

my section of code where I increment comparisons and swaps

// merge arrays until reaching end of either while (leftIndex <= middle && rightIndex <= right) { comparisonCount++; // place smaller of two current elements into result // and move to next space in arrays if (tempArray[leftIndex] <= tempArray[rightIndex]) { swapCount++; combinedArray[combinedIndex++] = tempArray[leftIndex++]; } else { swapCount++; combinedArray[combinedIndex++] = tempArray[rightIndex++]; } }