Best Time to Buy and Sell Stock
accepted answer:
class Solution(object):
def maxProfit(self, prices):
"""
:type prices: List[int]
:rtype: int
"""
l, r = 0, 1
res = 0
while r < len(prices):
if prices[l] < prices[r]:
profit = prices[r] - prices[l]
res = max(res, profit)
else:
l = r
r += 1
return res