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 */

package insertionsort;

/**
 *
 * @author suchenek
 */
public class InversionCounter {


    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
           int[] Array;
           int N;
 for (N = 1; N<=100; N++)
 {
        Array = new int[N];
        for (int i = 0; i < N; i++)
        Array[i] = (int)(Math.sqrt(97)*(13*i + 1)*(19*i + 2)+i - 17)%1000;
//        for (int i = 0; i < N; i++)
//        Array[i] = -i;
       int[] ReversedArray = new int[N];
        for (int i = 0; i < N; i++)
        ReversedArray[i] = Array[N-i -1];

        int invA = InversionCounter.Go(Array);
        int invR = InversionCounter.Go(ReversedArray);
        System.out.println("Array[" + N + "] has " + invA + " inversions out of max " + (N*(N-1)/2));
        System.out.println("ReversedArray[" + N + "] has " + invR + " inversions out of max " + (N*(N-1)/2));
        System.out.println("Both arrays have a total of " + (invA + invR) + " inversions out of max " + (N*(N-1)/2));
        System.out.println();
 }
}

    public static int Go(int [] A)
    {
        int n = A.length;
        if (n <= 1) return 0;
        int count = 0;
        for (int i = 0; i < n-1; i++)
        {
            for (int j = i+1; j < n; j++)
            {
                if (A[i] > A[j]) count++;
            }
        }
        return count;
    }

}