<p>You are given an array <code>prices</code> where <code>prices[i]</code> is the price of a given stock on the <code>i<sup>th</sup></code> day.</p> <p>Find the maximum profit you can achieve. You may complete <strong>at most two transactions</strong>.</p> <p><strong>Note:</strong> You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> prices = [3,3,5,0,0,3,1,4] <strong>Output:</strong> 6 <strong>Explanation:</strong> Buy on day 4 (price = 0) and sell on day 6 (price = 3), profit = 3-0 = 3. Then buy on day 7 (price = 1) and sell on day 8 (price = 4), profit = 4-1 = 3.</pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> prices = [1,2,3,4,5] <strong>Output:</strong> 4 <strong>Explanation:</strong> 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. </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> prices = [7,6,4,3,1] <strong>Output:</strong> 0 <strong>Explanation:</strong> In this case, no transaction is done, i.e. max profit = 0. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= prices.length <= 10<sup>5</sup></code></li> <li><code>0 <= prices[i] <= 10<sup>5</sup></code></li> </ul>