class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int res = 0;  
        // 遇到能当前天比前一天价格高，就前一天买入，当前天卖出
        for (int i = 1; i < prices.size(); ++i)
            if(prices[i] - prices[i - 1] > 0)
                res += prices[i] - prices[i - 1];
        return res;
    }
};

static int x=[](){
    std::ios::sync_with_stdio(false);
    cin.tie(NULL);
    return 0;
}();