Compilare: user.cpp: In function ‘int main()’: user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sumfact.in","r",stdin); ^ user.cpp:11:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sumfact.out","w",stdout); ^ user.cpp:13:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&n); ^ user.cpp:32:2: warning: ‘m’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i=1;i<=m;i++) ^