leetcode 121

class Solution_TimeLimit
{
	int maxprofit=0;
	if(prices.length==0)
		return 0;
	for(int i=0;i<prices.length-1;i++)
	{
		for(int j=i+1;j<prices.length;j++)
		{
			if(maxprofit<prices[j]-prices[i])
				maxprofit=prices[j]-prices[i];
		}
	}
	return maxprofit;
}
class Solution {
    public int maxProfit(int[] prices) {
		if(prices.length<2)
			return 0;
		if(prices.length==2)
			return prices[1]-prices[0]>0?(prices[1]-prices[0]):0;
                int maxprofit=prices[prices.length-1]-prices[prices.length-2];
		int maxprices=prices[prices.length-1];
                for(int j=prices.length-2;j>=0;j--)
		{
			if(maxprofit<maxprices-prices[j])
				maxprofit=maxprices-prices[j];
			if(maxprices<prices[j])
				maxprices=prices[j];
		}
		
		return maxprofit>0?maxprofit:0;
    }
}
class Test121 
{
	public static void main(String[] args) 
	{
		int[] prices={1,3,5,2,1,3,4,6,4,2,4,9,3,4,5,6};
		Solution s = new Solution();
		System.out.println(s.maxProfit(prices));
	}
}