Compilare: user.cpp: In function ‘void BackTrack(int, long long int, int)’: user.cpp:60:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lvl == Factorisation.size()) ^ user.cpp: In function ‘int main()’: user.cpp:102:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("autobuze.in", "r", stdin); ^ user.cpp:103:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("autobuze.out", "w", stdout); ^ user.cpp:105:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:108:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^