Merge sort (interview task)

MergeSort.java

package interview;

public class MergeSort {

    public void sort(int[] data) {
        if (data == null || data.length <= 1) {
            return;
        }
        sort(data, 0, data.length - 1);
    }

    private void sort(int[] data, int low, int high) {
        if (high == low) {
            return;
        }

        int half = (low + high) / 2;
        sort(data, low, half);
        sort(data, half + 1, high);

        int[] result = new int[high - low + 1];

        int resultIndex = 0;
        int lowIndex = low;
        int highIndex = half + 1;
        while (lowIndex <= half && highIndex <= high) {
            result[resultIndex++] = data[lowIndex] < data[highIndex]
                    ? data[lowIndex++]
                    : data[highIndex++];
        }
        while (lowIndex <= half) {
            result[resultIndex++] = data[lowIndex++];
        }
        while (highIndex <= high) {
            result[resultIndex++] = data[highIndex++];
        }
        System.arraycopy(result, 0, data, low, result.length);
    }

}