Compilare: user.cpp: In function ‘int main()’: user.cpp:20: warning: format ‘%ld’ expects type ‘long int*’, but argument 2 has type ‘int*’ user.cpp:18: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result