Best time to buy and sell stock iv

class Solution:
    def maxProfit(self, k: int, prices: List[int]) -> int:
        n = len(prices)
        dp = [[[0 for _ in range(2)] for _ in range(k + 1)] for _ in range(n)]
        for i in range(n):
            for j in range(k, 0, -1):
                if i == 0:
                    dp[0][j][0] = 0
                    dp[0][j][1] = -prices[i]
                    continue
                dp[i][j][0] = max(
                    dp[i - 1][j][0],
                    dp[i - 1][j][1] + prices[i],
                )
                dp[i][j][1] = max(
                    dp[i - 1][j][1],
                    dp[i - 1][j - 1][0] - prices[i],
                )
        return dp[n - 1][k][0]

Best Time to Buy and Sell Stock IV

Difficulty: Hard

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

Find the maximum profit you can achieve. You may complete at most k transactions: i.e. you may buy at most k times and sell at most k times.

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

 

Example 1:

Input: k = 2, prices = [2,4,1]
Output: 2
Explanation: Buy on day 1 (price = 2) and sell on day 2 (price = 4), profit = 4-2 = 2.

Example 2:

Input: k = 2, prices = [3,2,6,5,0,3]
Output: 7
Explanation: Buy on day 2 (price = 2) and sell on day 3 (price = 6), profit = 6-2 = 4. Then buy on day 5 (price = 0) and sell on day 6 (price = 3), profit = 3-0 = 3.

 

Constraints:

  • 1 <= k <= 100
  • 1 <= prices.length <= 1000
  • 0 <= prices[i] <= 1000