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EECS 209 Case Western Reserve University

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/* * Name: Shreyas Tallamraju * EECS 233 - Case Western Reserve University * Prof. Rabinovich * Version 3.6 * Latest Date: 04/19/2015 * */ //a utility class with 3 sorting methods; heap-sort, quick-sort, and merge-sort //every sorting method is explained in great detail with comments public class Sorting { public static long heapSort(int [] arr) { //error catching if(arr == null){System.out.println("Incorrect Input!"); return -1;} //end of error catching //start timer long startTime = System.nanoTime(); //START METHOD //EXPLANATION OF METHOD: //starting from the beginning of array, the values in array are manipulated into a max-on-top heap. //then, elements are removed (just like removeMax()) from the heap and added …show more content…

private static void partition(int[] arr, int first, int last) { int left = first;//set a temporary placeholder to first int right = last;//set a temporary placeholder to last //calculating pivot number by finding the middle index //*****HERE IS THE PIVOT SELECTION CODE******* int pivot = arr[first+(last-first)/2];//in the lecture, this way was used to find the pivot (middle value) //*****END OF PIVOT SELECTION CODE************ //divide into two arrays while (left <= right)//while loop will run as long as left is less or equal to right { while (arr[left] < pivot){//while loop that increments left up until the value at index left is less than the pivot left++; } while (arr[right] > pivot){//while loop that subtracts 1 from right until value at index right is greater than pivot right--; } if (left <= right)//test if left is equal or less than right { int temporaryValue = arr[left];//if so, swap left and right arr[left] = arr[right]; arr[right] = temporaryValue; //iterate both values

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