Compilare: user.cpp: In function ‘void DFs(long int)’: user.cpp:28: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void DFs_2(long int)’: user.cpp:71: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:116: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long int’ user.cpp:92: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:93: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result