QuickSort

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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; } }