python | #买卖股票的最好时机#

#
# 
# @param prices int整型一维数组 
# @return int整型
#
class Solution:
    def maxProfit(self , prices ):
        # write code here
        p_min = prices[0]
        p_now = prices[0]
        best = 0
        for p in prices:
            if p<p_min:
                p_min = p
            else :
                p_now = p 
                best = max(p_now - p_min,best)
        return best