mergesort.java

实现了jtree和jtable的联合功能

public abstract class MergeSort extends Object {
    protected Object           toSort[];
    protected Object           swapSpace[];

    public void sort(Object array[]) {
        if(array != null && array.length > 1)
        {
            int             maxLength;

            maxLength = array.length;
            swapSpace = new Object[maxLength];
            toSort = array;
            this.mergeSort(0, maxLength - 1);
            swapSpace = null;
            toSort = null;
        }
    }

    public abstract int compareElementsAt(int beginLoc, int endLoc);

    protected void mergeSort(int begin, int end) {
        if(begin != end)
        {
            int           mid;

            mid = (begin + end) / 2;
            this.mergeSort(begin, mid);
            this.mergeSort(mid + 1, end);
            this.merge(begin, mid, end);
        }
    }

    protected void merge(int begin, int middle, int end) {
        int           firstHalf, secondHalf, count;

        firstHalf = count = begin;
        secondHalf = middle + 1;
        while((firstHalf <= middle) && (secondHalf <= end))
        {
            if(this.compareElementsAt(secondHalf, firstHalf) < 0)
                swapSpace[count++] = toSort[secondHalf++];
            else
                swapSpace[count++] = toSort[firstHalf++];
        }
        if(firstHalf <= middle)
        {
            while(firstHalf <= middle)
                swapSpace[count++] = toSort[firstHalf++];
        }
        else
        {
            while(secondHalf <= end)
                swapSpace[count++] = toSort[secondHalf++];
        }
        for(count = begin;count <= end;count++)
            toSort[count] = swapSpace[count];
    }
}