It is a back to back interview. The questions are easy and basic. One guy is from Ads group, the other is from map group. I didn't fully prepare it. So the conversation was not happy.

Interview Questions
1. Write a function to swap to data in any type.
2. Given a list of ASII and utf-8 characters, return if the characters are actually valid.
3. Given a group of 2D points. Write a function to find whether there is any vertical line that can separate the group of points into 2 symmetric groups.
4. Convert strings like aabbcccc to string like a2b2c4?