Leetcode:714. Best Time to Buy and Sell Stock with Transaction Fee

c++:

class Solution {public:    int maxProfit(vector<int>& prices, int fee) {        int len = prices.size();        vector<int> maxProfit(len), cashWhenHoldOne(len);        maxProfit[0] = 0, cashWhenHoldOne[0] = -prices[0];        for (int i = 1; i < len; i++) {            maxProfit[i] = max(maxProfit[i-1], cashWhenHoldOne[i-1] + prices[i] - fee);            cashWhenHoldOne[i] = max(cashWhenHoldOne[i-1], maxProfit[i-1] - prices[i]);        }        return maxProfit[len-1];    }};