public void sort(int[] arr) {
    int len = arr.length;
    int step = len/2;
    while (step > 0) {
        for (int i = 0; i < step; i++) {
            for (int j = i + step; j < len; j += step) {
                int n = j;
                while (n - step >= 0) {
                    if (arr[n] >= arr[n - step]) break;
                    int temp = arr[n];
                    arr[n] = arr[n - step];
                    arr[n - step] = temp;
                    n -= step;
                }
            }
        }
        step /= 2;
    }
}

private void quickSort(int[] arr, int start, int end) {
    int left = start;
    int right = end;
    if (end - start < 1) return;
    int tempValue = arr[start];
    while (left != right) {
        while (left != right && arr[right] > tempValue) {
            right--;
        }
        swap(arr, left, right);
        while (left != right && arr[left] <= tempValue) {
            left++;
        }
        swap(arr, left, right);
    }

    quickSort(arr, start, left - 1);
    quickSort(arr, left + 1, end);
}

public static void main(){
    System.out.println("This is java code.");
}