https://codeforces.com/contest/1229/problem/CStraight forward solution runs in O(Q sqrt(N)). Let's prove this fact by potential analysis. We define the potential of this problem as the sum of the degrees of the vertices whose in-degree is …

https://codeforces.com/contest/1229/problem/DConsider this problem : How many permutations can be represented by the product of P[L] ... P[R]? In other words, please find the order of the group generated by P[L] ... P[R]. Then, this answer…