#+ANKI_DECK: study_deck_02
* TODO 0121. Best Time to Buy And Sell Stock :easy:
:PROPERTIES:
:NEETCODE: [[file:../../roadmap.org::*0121. Best Time to Buy And Sell Stock][0121. Best Time to Buy And Sell Stock]]
:END:

You are given an array ~prices~ where ~prices[i]~ is the price of a given stock on the ~i^{th}~ day.

You want to maximize your profit by choosing a *single day* to buy one stock and choosing a *different day in the future* to sell that stock.

Return /the maximum profit you can achieve from this transaction/. If you cannot achieve any profit, return ~0~.

*Example 1:*


#+begin_src
Input: prices = [7,1,5,3,6,4]
Output: 5
Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
#+end_src


*Example 2:*


#+begin_src
Input: prices = [7,6,4,3,1]
Output: 0
Explanation: In this case, no transactions are done and the max profit = 0.
#+end_src


*Constraints:*

 - ~1 <= prices.length <= 10^{5}~

 - ~0 <= prices[i] <= 10^{4}~

** TODO Approach
Write your approach here.

** TODO Python
#+begin_src python
class Solution:
    def maxProfit(self, prices: List[int]) -> int:
#+end_src

** TODO C++
#+begin_src cpp
class Solution {
public:
    int maxProfit(vector<int>& prices) {
        
    }
};
#+end_src