Array_best-time-to-buy-and-sell-stock.cpp

https://leetcode.com/problems/best-time-to-buy-and-sell-stock/

You are given an array prices where prices[i] is the price of a given stock on the ith 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:

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.
Example 2:

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

Constraints:

1 <= prices.length <= 105
0 <= prices[i] <= 104

class Solution {
public:
    int maxProfit(vector<int>& prices) {

        int ans = 0;
        int min_price = prices[0];
        int profit = 0;

        for(int i = 1; i < prices.size(); ++i)
        {
            int cur_price = prices[i];

            if(cur_price < min_price)
            {
               min_price = cur_price;
            }
            else
            {
                profit = max(cur_price - min_price, profit);
            }
        }

        return profit;
        
    }
};