[leetcode]Best Time to Buy and Sell Stock

class Solution {
public:
    int maxProfit(vector<int> &prices) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        int min_price = INT_MAX;
        int res = 0;
        for (size_t i = 0; i < prices.size(); i++) {
            min_price = min(min_price, prices[i]);
            res = max(res, prices[i] - min_price);
        }
        return res;
    }
};