public int subMaxProfit(int[] prices, int start, int end){
		 if(start >= end) return 0;
		 
		 int maxProfit = 0;
		 int min = start;
		 
		 for(int i=start + 1; i<=end; i++){
			 if(prices[i] - prices[min] > maxProfit) maxProfit = prices[i] - prices[min];
			 if(prices[i] < prices[min]) min = i;
		 }
		 
		 return maxProfit;
	 }