Compilare: user.cpp: In function ‘int solve(int)’: user.cpp:159:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] ok &= e[i].size() == D - 1; ^ user.cpp: In function ‘int main()’: user.cpp:253:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divizori2.in","r",stdin); ^ user.cpp:254:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divizori2.out","w",stdout); ^