I'm trying to solve this problem on LightOJ. What i've done is to calculate the total perimeter of the hull points and then add the additional curved portion as (pi-theta)*r [from picture below]

But i'm getting wrong answer. Is my approach wrong?

I'm getting wrong answer on test 34. Spent much time on it. Can't find the bug :( Can anyone tell me what i'm doing wrong?

490C: Hacking cypher

my submission

How can i filter the problemset so that it shows only div2 C's of all contests?