@yerich wroteI would say that your changes are 50/50. I say this because your marks aren't spectacular, but they're not bad either. A 90+ in two math courses helps you out, but I would try very hard to get that Calculus mark up. Your 75% in English probably isn't that big of a deal; I know someone who got into Waterloo CS with a 57% in Grade 12 English (but 90%+ in Maths and Sciences). Your Euclid mark of 69 is quite good, and will help you. If you manage to get a 90% instead of 80% in Calculus, I would expect that your chances would go up significantly.
Don't listen to Procrastinater; the average to get into CS is nowhere near 95%. I'd say 90% is a much better average, and 84% is a good minimum.
Dangit! I slacked off too much in Calculus! I could've gotten better but I just got too arrogant and didn't think I'd have to put any effort in... well, I guess I'll have to hope for the best.