class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int result = 0;
        int minPrice = 100000;

        for(int& price : prices) {
            // find minPrice
            // if price is smaller than minPrice, replace minPrice
            // else, stock can be selled, compare to the result
            if(price < minPrice){
                minPrice = price;
            } else {
                result = max(result, price - minPrice);
            }
        }

        return result;
    }
};