Merge and MergeSort Algorithms for Sorting Arrays in Java

[courtrigrad]

Hello all

Let's say we have the following classes:

 public class Merge {
protected static void merge(int[] a, int first, int last, int middle) {

        int i, j, k;
        int[] tempArray = new int[a.length];
        i = first;
        j = first;
        k = middle + 1;

        while(j <= middle && k <= last){
            if(a[j] <= a[k])
                tempArray[i++] = a[j++];
            else
                tempArray[i++] = a[k++];
        }
        while(j <= middle)
            tempArray[i++] = a[j++];
        while(k <= last)
            tempArray[i++] = a[k++];

        for (i = first; i <= last; i++)
            a[i] = tempArray[i];
        }
    }

and

 public class MergeSort extends Merge {
public static void mergeSort(int[] a, int first, int last) {

        if(last==first) return;
        if (last - first == 1) {
            //  not a[0]>a[1]; this part could test on the upper half of the array
            if (a[first] > a[last]) {
                int temp = a[first];
                a[first] = a[last];
                a[last] = temp;
            }
            

        } else {
            int halfwayPoint = (int) (last + first) / 2;
            mergeSort(a, first, halfwayPoint);
            mergeSort(a, halfwayPoint + 1, last);
            merge(a, first, last, halfwayPoint);
           
        }
    }
}

How would I print the array? I am stuck. I wrote the two classes but don't know how to get the output. Do I need a for loop?

Thanks

 

[Nylex]

Yeah, just use a for loop to go through each element in turn and print using System.out.println():

for(int i = 0; i < array.length(); i++)
[indent]System.out.println(array[i]);[/indent]

HTH.

 

[courtrigrad]

thanks a bunch