Class to implment three way partition quick sort
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39
Sorting/QuickSorterThreeWay.java
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39
Sorting/QuickSorterThreeWay.java
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package Sorting;
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/**
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* an implementation of quick sort with three-way partitioning
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*/
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public class QuickSorterThreeWay extends QuickSorter{
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public QuickSorterThreeWay(String filename){
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super("3-way partitioned quick", filename);
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}
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//edit this to use three-way partition
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@Override
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private void quickSort(int lowIndex, int highIndex){
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if(compare(lowIndex,highIndex)<0){
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int pivot = partition(lowIndex, highIndex);
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quickSort(lowIndex, pivot-1);
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quickSort(pivot+1, highIndex);
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}
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}
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//edit this to use three way partition
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@Override
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private int partition(int lowIndex, int highIndex){
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int pivot = numbers[highIndex];
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int i = lowIndex-1;
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for(int j=lowIndex;j<highIndex;j++){
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if(compare(numbers[j],pivot)<0){
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i++;
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swap(i,j);
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}
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}
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swap(i+1, highIndex);
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return i+1;
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}
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}
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