Compilare: user.cpp: In function ‘int main()’: user.cpp:81: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:82: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:83: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:86: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:89: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘bool lowest_level()’: user.cpp:47: warning: ‘ret’ may be used uninitialized in this function /tmp/ccNF5M8c.o: In function `main': user.cpp:(.text+0x295): warning: the `gets' function is dangerous and should not be used.