Compilare: user.cpp: In function ‘void expand2(int, int)’: user.cpp:55: warning: comparison between signed and unsigned integer expressions user.cpp:60: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int df(int)’: user.cpp:70: warning: unused variable ‘ok’ user.cpp: In function ‘int main()’: user.cpp:89: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:90: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:92: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:95: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:100: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result