Best_time_to_buy_and_sell_stock.cpp

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