It is an algorithm question whose topic is : Best Time to Buy and Sell Stock
Say you have an array for which the ith 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.
*Example 1: Input: [7, 1, 5, 3, 6, 4] Output: 5
max. difference = 6-1 = 5 (not 7-1 = 6, as selling price needs to be larger than buying price).*
*Example 2: Input: [7, 6, 4, 3, 1] Output: 0
In this case, no transaction is done, i.e. max profit = 0.*
I worked it out using python. Codes are as follows:
class Solution(object):
def maxProfit(self, prices):
"""
:type prices: List[int]
:rtype: int
"""
i=Max=0
if not prices:
return 0
while i+1 <= len(prices)-1:
j=i+1
while j < len(prices):
if prices[i] < prices[j]:
Max = max(Max, prices[j] - prices[i])
j+=1
j+=1
i+=1
return Max
However, the system returned me that I was wrong: Return wrong
Tried but I can't figure out where the error is... Can someone help please ? Thanks a lot!