UCB is a special case, because you can major in CS two different ways:
- EECS in the College of Engineering: more selective, but direct admission to the major. However, a higher volume of requirements may make taking pre-med courses more difficult.
- CS in the College of Letters and Science (L&S): since all L&S students start undeclared, major within L&S does not affect selectivity per se (although consistency of essays and ECs can affect how a reader sees your application). L&S students need to earn a 3.3 GPA in three CS courses to get into the L&S CS major (about half of students in those courses earn B+ or higher grades). Leaves more schedule space to take pre-med courses.
However, as a non-California resident, UCB will be expensive with no financial aid, unless you get a super-reach Regents’ scholarship. Spending more on undergraduate will make it harder to afford medical school, or require a longer term of debt service if you do go to medical school.
Regarding pre-med at UCB, about a quarter of students in typical pre-med courses earn A- or higher grades. If you get mostly grades lower than A-, you are unlikely to get into a US medical school.
Here is an older post about grade distributions for selected courses at UCB:
http://talk.collegeconfidential.com/university-california-berkeley/2071932-grade-distributions-in-prerequisite-courses-for-gpa-based-goals.html
For grade distributions by course at some other colleges, see here:
http://talk.collegeconfidential.com/pre-med-topics/2074436-some-colleges-have-grade-distribution-information-available-by-course.html