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

[Easy]

• 121. Best Time to Buy and Sell Stock

[Medium]

• 122. Best Time to Buy and Sell Stock II
• 309. Best Time to Buy and Sell Stock with Cooldown
• 714. Best Time to Buy and Sell Stock with Transaction Fee

[Hard]

• 123. Best Time to Buy and Sell Stock III
• 188. Best Time to Buy and Sell Stock IV