Compilare: main.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas] #pragma GCC optimization ("O3") main.cpp:4:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas] #pragma GCC optimization ("unroll-loops") main.cpp: In member function 'void p_hash::build(std::__cxx11::string)': main.cpp:39:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(pow1.size() <= n) { ~~~~~~~~~~~~^~~~