Compilare: main.cpp: In function 'bool tryy(std::vector<int>)': main.cpp:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < sol.size() - 1; i++){ ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:89:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size() / 2; i++){ ~~^~~~~~~~~~~~~~~~