Compilare: user.cpp: In function ‘bool Euler(int)’: user.cpp:48: warning: comparison between signed and unsigned integer expressions user.cpp:58: warning: comparison between signed and unsigned integer expressions user.cpp:59: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:92: warning: comparison between signed and unsigned integer expressions user.cpp:68: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:69: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:71: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:75: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:82: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result /tmp/ccXroZYG.o: In function `main': user.cpp:(.text+0xaba): warning: the `gets' function is dangerous and should not be used.