Are there any good rules of thumb on when a square root decomposition will be too slow? I suspect if we have an interval of length 10⁵ and 3 × 10⁵ queries a square root decomposition is too slow but this is only based on my attempts to solve http://codeforces.net/problemset/problem/765/F with a square root decomposition where I calculated the complexity of my algorithm to be and exceeding the time limit. In general if you are given an interval of length N and Q queries what sort of values of do you want in order to be confident that a square root decomposition will pass the time constraint? Also are there standard limits used in Codeforces deliberately set to prevent square root decomposition based approaches?