Maximize Stock Trading Profit

You are given an array prices, representing stock prices over N consecutive days. Your goal is to compute the maximum profit achievable by performing multiple transactions (i.e., buying one share and then selling one share multiple times).

Note: You must sell a stock before buying again.

Input:

N  
prices[0] prices[1] ... prices[N-1]

Output:

maximum_profit

Example:

Input:

6  
7 1 5 3 6 4

Output:

7

Explanation:

The maximum profit can be achieved by buying on day 2 (at price 1) and selling on day 3 (at price 5), profit = 5-1 = 4. Then buying again on day 4 (at price 3) and selling on day 5 (at price 6), profit = 6-3 = 3. Total profit is 4 + 3 = 7.

Constraints:

• 1 <= N <= 5 * 10⁴
• 0 <= prices[i] <= 10⁴
• Time Limit: 1 second