Ask HN: How do I learn math for problem solving in CS?

My CS career started from High School, where I learned data structures and algorithms, and used them in problem solving competitions/olympiads and I still do (ACM-ICPC, TopCoder). I feel confident in applying these data structures and algorithms to a real world problems. Since I'm passionate in problem solving. But I feel that I'm missing one important thing - math. Math (Number Theory, Probability, Geometry and every topic CS student should now in this field) which will help one to come up with a solution and make one able to prove this solution. If you know how can I fill this gap, or materials which will help me to do that, please, share them with me. I really want to become better at problem solving. Thanks in advance!

PS. I am novice here. If someone else already asked a similar question, please, send the link and I will delete this post.