121. Best Time to Buy and Sell Stock

class Solution 
{
    public int maxProfit(int[] prices) 
    {
        int p=prices[0];
        int s=0;
        for(int i=1;i<prices.length;i++)
        {
            if(prices[i]>p && prices[i]-p>s)
                s=prices[i]-p;
            else if(prices[i]<p)
                p=prices[i];
        }
        return s;
    }
}