Up to two stock trades-best time to Buy and Sell stock III

Say you has an array for which the i-th element is the price of a given-stock on day I.

Design an algorithm to find the maximum profit. Transactions. (Stock trading , up to two times)

Note:
Engage in multiple transactions on the same time (ie, you must sell the stock before you buy again).

Class Solution {public:    int maxprofit (vector<int> &prices) {        if (prices.size () ==0) return 0;        int n=prices.size ();        Vector<int> left (n);        Vector<int> right (n);        int min=prices[0];        int max=prices[n-1];        int res=0;        for (int i=1;i<n;i++)        {            min=min<prices[i]?min:prices[i];            Left[i]=left[i-1]> (prices[i]-min) left[i-1]:(prices[i]-min);        }        for (int j=n-2;j>=0;j--)        {            max=max>prices[j]?max:prices[j];            Right[j]=right[j+1]> (Max-prices[j]) right[j+1]:(max-prices[j]);        }        for (int i=0;i<n;i++)        {            res=res> (Left[i]+right[i]) Res: (Left[i]+right[i]);        }        return res;    }};

　　

Up to two stock trades-best time to Buy and Sell stock III