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).
Test Cases
Input:
(int[]) prices = [3,3,5,0,0,3,1,4]
Output:
(int) 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.
Input:
(int[]) prices = [1,2,3,4,5]
Output:
(int) 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.
Input:
(int[]) prices = [7,6,4,3,1]
Output:
(int) 0
Explanation:
In this case, no transaction is done, i.e. max profit = 0.
Solution
class Solution {
public:
int maxProfit(vector<int>& prices) {
int oneBuy = INT_MIN, oneBuyOneSell = 0;
int twoBuy = INT_MIN, twoBuyTwoSell = 0;
for(int i=0; i<prices.size(); i++) {
oneBuy = max(oneBuy, -prices[i]);
oneBuyOneSell = max(oneBuyOneSell, oneBuy + prices[i]);
twoBuy = max(twoBuy, oneBuyOneSell -prices[i]);
twoBuyTwoSell = max(twoBuyTwoSell, twoBuy + prices[i]);
}
return max(oneBuyOneSell, twoBuyTwoSell);
}
};import java.util.*;
class Solution {
public int maxProfit(int[] prices) {
int oneBuy = Integer.MIN_VALUE, oneBuyOneSell = 0;
int twoBuy = Integer.MIN_VALUE, twoBuyTwoSell = 0;
for(int i=0; i<prices.length; i++) {
oneBuy = Math.max(oneBuy, -prices[i]);
oneBuyOneSell = Math.max(oneBuyOneSell, oneBuy + prices[i]);
twoBuy = Math.max(twoBuy, oneBuyOneSell -prices[i]);
twoBuyTwoSell = Math.max(twoBuyTwoSell, twoBuy + prices[i]);
}
return Math.max(oneBuyOneSell, twoBuyTwoSell);
}
public static void main(String[] args) {
Solution solution = new Solution();
int[] prices = new int[]{3,3,5,0,0,3,1,4};
System.out.println(solution.maxProfit(prices));
}
}from typing import List
class Solution:
def maxProfit(self, prices: List[int]) -> int:
ob, tb = float('-inf'), float('-inf')
obos, tbts = 0, 0
for price in prices:
ob = max(ob, -price)
obos = max(obos, ob + price)
tb = max(tb, obos - price)
tbts = max(tbts, tb + price)
return max(obos, tbts)
if __name__ == '__main__':
prices = [3, 3, 5, 0, 0, 3, 1, 4]
solution = Solution()
print(solution.maxProfit(prices))