Best Time to Buy and Sell Stock II — JavaScript Coding Problem
Difficulty: easy | Category: greedy
Problem Description
You are given an integer array `prices` where `prices[i]` is the price of a given stock on the `i`-th day. On each day, you may decide to buy and/or sell the stock. You can only hold **at most one share** of the stock at any time. However, you can buy it then immediately sell it on the **same day**. Find and return the **maximum profit** you can achieve.
Examples
Example 1
Input: prices = [7,1,5,3,6,4]
Output: 7
Explanation: Buy on day 2 (price=1), sell on day 3 (price=5). Buy on day 4 (price=3), sell on day 5 (price=6). Total profit = 4 + 3 = 7.
Example 2
Input: prices = [1,2,3,4,5]
Output: 4
Explanation: Buy on day 1, sell on day 5. Profit = 5-1 = 4.
Example 3
Input: prices = [7,6,4,3,1]
Output: 0