Be careful of the semester/quarter difference. 1 semester credit (as at W&M) = 1.5 quarter credit (as at Washington). W&M requires 120 semester credits to graduate, while Washington requires 180 quarter credits to graduate.
W&M CS requires 3 lower level CS courses and 9 upper level CS courses, most of which are 3 credits (the first one is 4 credits), so probably 37 semester credits. Note that 37 semester credits = 55.5 quarter credits.
Washington CS requires 87-90 quarter credits, of which 62 quarter credits are CS courses (the rest are math and non-CS science). Note that 62 quarter credits = 41+1/3 semester credits.