Original Quick.java: /**********************************************************

Question

Original Quick.java:

/******************************************************************************
* Compilation: javac Quick.java
* Execution:    java Quick < input.txt
* Dependencies: StdOut.java StdIn.java
*  
* % more tiny.txt
* S O R T E X A M P L E
*
* % java Quick < tiny.txt
* A E E L M O P R S T X                 [ one string per line ]
******************************************************************************/

public class Quick {

    public static void sort(Comparable[] a) {
        sort(a, 0, a.length - 1);
    }

    // quicksort the subarray from a[lo] to a[hi]
    private static void sort(Comparable[] a, int lo, int hi) {
        if (hi <= lo) return;
        int j = partition(a, lo, hi);
        sort(a, lo, j-1);
        sort(a, j+1, hi);
    }

    // partition the subarray a[lo..hi] so that a[lo..j-1] <= a[j] <= a[j+1..hi]
    // and return the index j.
    private static int partition(Comparable[] a, int lo, int hi) {
        int i = lo;
        int j = hi + 1;
        Comparable v = a[lo];
        while (true) {

            // find item on lo to swap
            while (less(a[++i], v)) {
                if (i == hi) break;
            }

            // find item on hi to swap
            while (less(v, a[--j])) {
                if (j == lo) break;      // redundant since a[lo] acts as sentinel
            }

            // check if pointers cross
            if (i >= j) break;

            exch(a, i, j);
        }

        // put partitioning item v at a[j]
        exch(a, lo, j);

        // now, a[lo .. j-1] <= a[j] <= a[j+1 .. hi]
        return j;
    }

   /***************************************************************************
    * Helper sorting functions.
    ***************************************************************************/
   
    // is v < w ?
    private static boolean less(Comparable v, Comparable w) {
        if (v == w) return false;   // optimization when reference equals
        return v.compareTo(w) < 0;
    }
       
    // exchange a[i] and a[j]
    private static void exch(Object[] a, int i, int j) {
        Object swap = a[i];
        a[i] = a[j];
        a[j] = swap;
    }

   /***************************************************************************
    * Check if array is sorted - useful for debugging.
    ***************************************************************************/
    // print array to standard output
    private static void show(Comparable[] a) {
        for (int i = 0; i < a.length; i++) {
            StdOut.println(a[i]);
        }
    }

    public static void main(String[] args) {
        String[] a = StdIn.readAllStrings();
        Quick.sort(a);
        show(a);
    }

}

Could you please revise or add to the original Quick.java program above to count precise number of compares and output results such as the ones below.

Before QuickSort: T L E X E A P R S M O

After QuickSort: A E E L M O P R S T X

There are 41 compares. NlgN = 38.05374780501027

Before QuickSort: Q U I C K S O R T E X A M P L E

After QuickSort: A C E E I K L M O P Q R S T U X

There are 71 compares. NlgN = 64

Explanation / Answer

output

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