后一个比前一个大就要操作买入卖出

    3. class Solution {
    4. public:
    5.     int maxProfit(vector<int>& prices) {
    6.         if(!prices.size()) return 0;
    7.         vector<int> val(prices.size(), 0);
    8.         for(int i = 1; i < prices.size(); i++)
    9.         {
    10.             if(prices[i] > prices[i - 1])
    11.                 val[i] = val[i - 1] + (prices[i] - prices[i - 1]);
    12.             else
    13.                 val[i] = val[i - 1];
    14.         }
    15.         return val[prices.size() - 1];
    16.     }
    17. };

    第二次写题

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