121. 买卖股票的最佳时机

题目链接：

https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock/

解题思路：

class Solution {
    public int maxProfit(int[] prices) {
        int max_diff = 0;
        int min_diff = Integer.MAX_VALUE;
        for(int i=0;i<prices.length;i++)
        {
            if(prices[i]<min_diff)
            {
                min_diff = prices[i];
            }
            
            if(max_diff<prices[i]-min_diff)
            {
                max_diff = prices[i]-min_diff;
            }
        }
        return max_diff;
    }
}