Tutoring-APCompSci/Sorting/WordQuickSorter.java

package Sorting;

public class WordQuickSorter extends Sorter{
    
    public WordQuickSorter(RandomWordFileReader reader) {
        super("quick sort", reader);
    }

    public WordQuickSorter(String type, RandomWordFileReader reader) {
        super(type, reader);
    }

    void sort() {
        quickSort(0, words.length-1);
    }

    void quickSort(int lowIndex, int highIndex) {
        if (lowIndex < highIndex) {
            int pivot = partition(lowIndex, highIndex);
            quickSort(lowIndex, pivot-1);
            quickSort(pivot+1, highIndex);
        }
    }

    private int partition(int lowIndex, int highIndex) {
        int i = lowIndex -1;
        String pivot = words[highIndex];
        for(int j = lowIndex; j < highIndex; j++) {
            if(compare(words[j], pivot) < 0) {
                i++;
                swap(words, i, j);
            }
        }
        swap(words, i+1, highIndex);
        return i+1;
    }

}