[LeetCode] Best Time to buy and sell stock

Say you have an array for which the i^th element is the price of a given stock on day i.
If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.

 解题思路：
    动态规划： 局部最优 以及 全局最优
    要获得最大收益，最理想的状态就是：在最低价买进，最高价卖出。
    在第 i 天卖出最大收益 profit[i] = price[i] - minPrice。
    在0...n中的最大收益就为 max(profit[0..n])
    在这个过程中最主要的就是要track出第i天的最小价格



java code:

 public int maxProfit(int[] prices) {
        int maxProfit = 0;
        int minPrice = Integer.MAX_VALUE;
        
        for(int i = 0; i < prices.length; i++){   
            minPrice = minPrice < prices[i]? minPrice : prices[i];
            int profit = prices[i] - minPrice;
            maxProfit = maxProfit > profit ? maxProfit : profit;
        }
          
        return maxProfit;
    }