Compilare: user.cpp: In function ‘int main()’: user.cpp:46:62: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sol[0] == sol[ sol.size() - 1 ] and sol.size() == m + 1){ ^ user.cpp:53:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<sol.size() - 1; ++i) ^