3. Best Time to Buy and Sell Stock
Given an array prices, return the maximum profit you can achieve from one buy and one sell.
Contoh 1:
Input: prices = [7,1,5,3,6,4] Output: 5
Contoh 2:
Input: prices = [7,6,4,3,1] Output: 0
Batasan:
1 <= prices.length <= 10^5