122. Best Time to Buy and Sell Stock II

//https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/
class Solution {
    // купить дешевле
    // продать дороже
public:
    int maxProfit(vector<int>& prices) {
        if(prices.empty()) return 0;
       int i = 0;
        int valley = prices[0];
        int peak = prices[0];
        int maxprofit = 0;
        while (i < prices.size() - 1) {
            while (i < prices.size() - 1 && prices[i] >= prices[i + 1])
                i++;
            valley = prices[i];
            while (i < prices.size() - 1 && prices[i] <= prices[i + 1])
                i++;
            peak = prices[i];
            maxprofit += peak - valley;
        }
        return maxprofit; 
    }
};