Compilare: user.cpp: In function ‘int main()’: user.cpp:40:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (sol != -1) ^ user.cpp:44:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i * i <= x; ++i) ^ user.cpp: In function ‘long long unsigned int caut(long long unsigned int, long long unsigned int)’: user.cpp:29:1: warning: control reaches end of non-void function [-Wreturn-type] } ^