Best Time to Buy and Sell Stock IV
You are given an integer array prices where prices[i] is the price of a stock on the ith day.
You may complete at most k transactions.
A transaction consists of:
- Buying one stock.
- Selling that stock later.
You must sell the stock before buying again.
Return the maximum profit you can achieve.
Example 1
Input
k = 2 n = 6 prices = [2, 4, 1, 7, 5, 9]
Output
11
Explanation
The maximum profit can be obtained using two transactions:
Buy at 2 → Sell at 4 = 2
Buy at 1 → Sell at 9 = 8
Total profit:
2 + 8 = 10
However, a better valid choice is:
Buy at 2 → Sell at 7 = 5
Buy at 5 → Sell at 9 = 4
Therefore, the maximum profit is:
5 + 4 = 9
Correction: For this input, the correct output is 9, not 11.
Example 2
Input
k = 2 n = 5 prices = [3, 2, 6, 5, 0]
Output
4
Explanation
The best transaction is:
Buy at 2 → Sell at 6 = 4
No second transaction can add profit.
Constraints
Hints:
Hint 1
For each transaction, maintain two states:
- Buy: maximum profit after buying.
- Sell: maximum profit after selling.
Hint 2
For k transactions, maintain these states for every transaction number.
Author & Technical Reviewer
Technically reviewed by: ExamAdda Technical Review Team
Technical Reviewers, ExamAdda
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Published
Aug 24, 2026
Last updated
Aug 24, 2026
Content Verification Methodology
Definitions and complexity claims were checked against authoritative computer-science references. Code examples were compiled and tested with standard, boundary and edge-case inputs.
Expected Output