Prepare for Doordash OA

Just got the OA for Doordash internship, can anyone give some advice on how to prepare for them? Level of difficulty, what kinds of leetcode etc. Thanks in advanced!

I got something identical to leetcode 547 and question 2 here https://leetcode.com/discuss/interview-experience/795608/PayPal-or-SDE-1-or-Bangalore-or-August-2020-Offer