Given an array prices where prices[i] is the price of a stock on day i, return the maximum profit you can achieve from a single buy and single sell. This is a clean recurrence-relations DP starter.
prices = stock prices by day
maximum profit from one transaction
Example 1:
Input:
prices = [7,1,5,3,6,4]
Output:
5
Explanation:
Buy at 1 and sell at 6.
Example 2:
Input:
prices = [7,6,4,3,1]
Output:
0
Explanation:
No profitable transaction is possible.