The first day, I talked to the recruiter on campus at the career fair. He said my resume and project experience were good and wanted to interview me further the next day on campus.

The second day, there was the interview on campus. Initially, they asked about my projects and my teamwork experience. Then they gave me three coding questions. I completed all three questions, but there has been no further contact.

1. Given some requirements, I need to write the code. It's very straightforward. I remember the question was like this: Given an array of integers, if there is an even index, double the value at that index. If, at the end, the sum of the elements is equal to some value, then the array is valid.

2. Given an array of integers, find the maximum difference between any two numbers.

3. If all those integers represent stock prices, find the maximum profit one transaction can gain.