> For the complete documentation index, see [llms.txt](https://cmmobile.gitbook.io/cmmobilebook/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cmmobile.gitbook.io/cmmobilebook/cheng-shi-lian-xi-ti/shu-zi-cao-zuo/best-time-to-buy-and-sell-stock-ii.md).

# Best Time to Buy and Sell Stock II

[題目](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/)

{% embed url="<https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/>" %}

Say you have an array `prices` for which the *i*th element is the price of a given stock on day *i*.

Design an algorithm to find the maximum profit. You may complete as many transactions as you like (i.e., buy one and sell one share of the stock multiple times).

**Note:** You may not engage in multiple transactions at the same time (i.e., you must sell the stock before you buy again).

**Example 1:**

```
Input: [7,1,5,3,6,4]
Output: 7
Explanation: 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.
```

**Example 2:**

```
Input: [1,2,3,4,5]
Output: 4
Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.
             Note that you cannot buy on day 1, buy on day 2 and sell them later, as you are
             engaging multiple transactions at the same time. You must sell before buying again.
```

**Example 3:**

```
Input: [7,6,4,3,1]
Output: 0
Explanation: In this case, no transaction is done, i.e. max profit = 0.
```

**Constraints:**

* `1 <= prices.length <= 3 * 10 ^ 4`
* `0 <= prices[i] <= 10 ^ 4`