public static int maxProfitSingle(int[] prices, int start, int end) {
		if (start >= end) {
			return 0;
		}
		int max = 0;
		int low = prices[start];
		for (int i = start; i <= end; i++) {
			if (prices[i] < low)
				low = prices[i];
			int diff = prices[i] - low;
			if (diff > max) {
				max = diff;
			}
		}
		return max;
	}