Best Time to Buy and Sell Stock II
Updated Jan 31, 2026
Problem
You are given an integer array prices where prices[i] is the price of a given stock on the ith day.
On each day, you may decide to buy and/or sell the stock. You can only hold at most one share of the stock at any time. However, you can buy it then immediately sell it on the same day.
Find and return the maximum profit you can achieve.
Constraints
1 <= prices.length <= 3 * 10^4
0 <= prices[i] <= 10^4
Examples
Example 1
Input:
prices = [7,1,5,3,6,4]
Output:
7
Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4. Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3. Total profit is 4 + 3 = 7.
Example 2
Input:
prices = [1,2,3,4,5]
Output:
4
Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.
Example 3
Input:
prices = [7,6,4,3,1]
Output:
0
There is no way to make a positive profit.
Function Signature
def maxProfit(self, prices: list[int]) -> int
How to Submit
Implement a Solution class with a maxProfit method.
Your method will be called with the input parameters and should return the answer.