1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 | import java.util.Arrays; /** * 3way quick sort in order to improve performance in case of too many duplicates , where normal * Quicksort subrouites averages to quadratic performance * @author Prateek * */ public class ModifiedQuickSort { private int arr[]; private int size; public static void main(String[] args) { int []testInput={6,3,6,4,2,6,8,2}; ModifiedQuickSort mdqs=new ModifiedQuickSort(); mdqs.sort(testInput); } public void sort(int input[]) { arr=input; size=input.length; modified3wayQsort(0,size-1); System.out.println(Arrays.toString(arr)); } /** * 3 WayQuick Sort * @param low * @param high */ void modified3wayQsort(int low,int high) { if(high <= low) return ; int l=low,r=high; int v=arr[low]; // Partioning element 1st element int pivot=l+1; while(pivot<=r) { if(arr[pivot] < v) { swap(pivot++,l++); } else if(arr[pivot] > v) { swap(pivot,r--); } else pivot++; } modified3wayQsort(low, l-1); modified3wayQsort(r+1, high); } /** * Swapping content * @param i * @param j */ private void swap(int i,int j) { int temp=arr[i]; arr[i]=arr[j]; arr[j]=temp; } } |
Hi everyone, I am maintaining this blog for sharing knowledge on Algorithms and Data Structures.
13 Sept 2013
QuickSort
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