Compilare: main.cpp:1: warning: ignoring '#pragma GCC compiler' [-Wunknown-pragmas] 1 | #pragma GCC compiler ("Ofast") | main.cpp:2: warning: ignoring '#pragma GCC compiler' [-Wunknown-pragmas] 2 | #pragma GCC compiler ("unroll-loops") | main.cpp: In function 'int main()': main.cpp:124:50: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 124 | for (int i=int(ans.size()) & 1; i<ans.size(); i+=2) | ~^~~~~~~~~~~