Best Time to Buy and Sell Stock.cpp

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

//Solution

class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int min = *max_element(prices.begin(), prices.end());
        int max = 0;
        for(int i=0; i<prices.size(); ++i)
        {
            if(prices[i] < min)
                min = prices[i];
            else if(prices[i] - min > max)
                max = prices[i] - min;
        }
        return max;
    }
};