Compilare: main.cpp: In instantiation of 'Decomposition<T>::Decomposition(std::vector<_Tp>&, std::function<T(T, T)>) [with T = long long int]': main.cpp:60:68: required from here main.cpp:12:23: warning: 'Decomposition<long long int>::f' will be initialized after [-Wreorder] function<T(T, T)> f; ^ main.cpp:9:9: warning: 'int Decomposition<long long int>::sz' [-Wreorder] int sz; ^~ main.cpp:13:5: warning: when initialized here [-Wreorder] Decomposition(vector<T> &a, function<T(T, T)> f) ^~~~~~~~~~~~~ main.cpp:17:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0, block_idx = 0; i < a.size(); i += block_size, ++block_idx) { main.cpp:19:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < block_size && i + j < a.size(); ++j) { main.cpp: In instantiation of 'T Decomposition<T>::get(int, int) [with T = long long int]': main.cpp:64:32: required from here main.cpp:48:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = l; i < a.size() && i < (lseg + 1) * block_size; ++i) {