For UCs, recalculate your GPAs using the method described at GPA Calculator for the University of California – RogerHub . This will give you unweighted, weighted-capped, and fully-weighted GPAs for UC purposes. Most UC web sites use weighted-capped unless otherwise indicated, though any which show GPAs greater than about 4.4 are likely using fully-weighted.
For CSUs, do the same recalculation and use weighted-capped, but double count college courses and grades (i.e. if you got an A in a semester college course, count that as two A grades in two courses if you are using semester grades in your high school courses).
CS can be much more selective than overall at many UCs and some CSUs. At such campuses, it can be very difficult to change into CS after enrolling as a different major or undeclared.