I conducted summer research with my Computer Science(CS) professor last summer. However, we were a group of three students. The end result was three papers written and all three of them contain our names in alphabetical order (so 4 names including our prof). Is this, the fact that it was more of team research and not one-on-one research with a professor, going to be looked down upon when I apply to Ph.D. programs in CS? Or does it make no difference at all?
No, it isn't going to hurt. Research that is published is not going to hurt any application in the US. It is going to help. And, collaboration is a valued skill in CS so that, too, is in your favor.
Even unpublished research mentioned by a letter writer is a plus. All such things are indicators of future success. And get the supervising professor to write a nice letter when you do apply. If that is a year or more in the future, let them know now of future plans.
This, and other questions you've asked here suggest you are overly concerned about the future. I'll predict that you will do fine and suggest you relax and stop overthinking.