Solution
from typing import List
import math
class Solution:
def maxProfit(self, prices: List[int]) -> int:
ans, mi = 0, math.inf
for v in prices:
ans = max(ans, v - mi)
mi = min(mi, v)
return ans
# ----------------本地测试----------------
if __name__ == "__main__":
sol = Solution()
print(sol.maxProfit([7,1,5,3,6,4])) # 5
print(sol.maxProfit([7,6,4,3,1])) # 0