Compilare: user.cpp: In function ‘int main()’: user.cpp:8:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("transport.in","r",stdin); ^ user.cpp:9:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("transport.out","w",stdout); ^ user.cpp:43:15: warning: ‘elem’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout<<elem; ^