For this week, you will need to be familiar with basic sorting algorithms and binary search. While you can mostly implement sorting algorithms using built-in functions, it would be good to know how the implementations or at least the properties of the most common sorting algorithms (insertion sort, bubble sort, selection sort, merge sort, and quick sort). You can find a good recap here.
If you want to try out a simple sorting-based problem, you can practice this:
Allocation - Google Kickstart 2021, Round A, Problem 1.
We will be implementing binary search in several situations. So it will be a good idea to be comfortable with the implementation of the basic binary search method. It sounds simple but you need to be careful about getting the corner cases right! You can read more about binary search here.