Today I have done leetcode's October LeetCoding Challenge with cpp.

October LeetCoding Challenge 15

Description

Best Time to Buy and Sell Stock with Cooldown

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 as many transactions as you like (i.e., buy one and sell one share of the stock multiple times) with the following restrictions:

• After you sell your stock, you cannot buy stock on the next day (i.e., cooldown one day).

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

Example 1:

Input: prices = [1,2,3,0,2]
Output: 3
Explanation: transactions = [buy, sell, cooldown, buy, sell]

Example 2:

Input: prices = [1]
Output: 0

Constraints:

• 1 <= prices.length <= 5000
• 0 <= prices[i] <= 1000

Solution

auto speedup = [](){
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  return 0;
}();
class Solution {
public:
  int maxProfit(vector<int>& prices) {
    int len = prices.size();
    if(len < 2) return 0;
    int buy[2] = {-prices[0], max(-prices[0], -prices[1])};
    int sell[2] = {0, max(0, buy[1] + prices[1])};
    for(int i = 2; i < len; ++i) {
      buy[0] = buy[1];
      buy[1] = max(buy[1], sell[0] - prices[i]);
      sell[0] = sell[1];
      sell[1] = max(sell[1], buy[0] + prices[i]);
    }
    return sell[1];
  }
};

// Accepted
// 210/210 cases passed (8 ms)
// Your runtime beats 32.2 % of cpp submissions
// Your memory usage beats 49.7 % of cpp submissions (11.3 MB)