Compilare: user.cpp: In function ‘void bac(int, long long int)’: user.cpp:39:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos == div.size()) ^ user.cpp: In function ‘int main()’: user.cpp:67:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("armonica.in", "r", stdin); ^ user.cpp:68:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("armonica.out", "w", stdout); ^ user.cpp:70:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &b); ^