Best Time to Buy and Sell Stock with Cooldown.cpp

class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int len = prices.size();
        if(len < 2)return 0;
        vector<int> dp(2, 0);
        dp[1] = max(0, prices[1] - prices[0]);
        int maxDiff = dp[0] - prices[2], e = 0;
        for(int i = 2; i < len; ++i, e ^= 1)
        {
            maxDiff = max(maxDiff, dp[e] - prices[i]);
            int localMax = max(maxDiff + prices[i], max(prices[i] - prices[0], prices[i] - prices[1]));
            dp[e] = max(dp[e ^ 1], localMax);
        }
        return dp[e ^ 1];
    }
};