Best Time to Buy and Sell Stock III

You are given an array prices where prices[i] is the price of a given stock on the ith day.

Find the maximum profit you can achieve. You may complete at most two transactions.

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

Example 1:

Input: prices = [3,3,5,0,0,3,1,4]
Output: 6
Explanation: 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.

Example 2:

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

Example 4:

Input: prices = [1]
Output: 0

Constraints:

• 1 <= prices.length <= 105

• 0 <= prices[i] <= 105

Solution:

class Solution {
    public int maxProfit(int[] prices) {
       if(prices.length<2) return 0;
        int k=2;
       int havingstock;
        int[][] nothavingstock = new int[k+1][prices.length+1];
               
        for(int t=1;t<=k;t++)
        {
        havingstock = -prices[0];
        for(int i=1;i<prices.length;i++)
        {
            havingstock = Math.max(havingstock,nothavingstock[t-1][i-1]-prices[i]);
            nothavingstock[t][i] = Math.max(nothavingstock[t][i-1],havingstock+prices[i]);
        }
                  
        }
        return nothavingstock[k][prices.length-1];
    }
}