# Codeforces Round #551 (Div. 2) F. Serval and Bonus Problem

https://codeforces.com/contest/1153/problem/FWithout loss of generality, we assume $L=1$. The probability that x is covered by a single interval is $2x(1-x)$. Let $f(x)=2x(1-x)$, then the expectation of the length covered by exactly …