122. Best Time to Buy and Sell Stock II (Leetcode)

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