(121)Best Time to buy and sell

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