public int[] sort(int[] a) {
		int left = 0;
		int right = a.length - 1;
		do {
			for (int i = left; i < right; i++) {
				if (a[i] > a[i + 1]) {
					int tmp = a[i + 1];
					a[i + 1] = a[i];
					a[i] = tmp;
				}
			}
			right--;
			for (int i = right; i > left; i--) {
				if(a[i]<a[i-1]){
					int tmp = a[i - 1];
					a[i - 1] = a[i];
					a[i] = tmp;
				}
			}
			left++;
		} while (left <= right);
		return a;
	}