Compilare: user.cpp: In function ‘int main()’: user.cpp:61:13: warning: unused variable ‘a’ [-Wunused-variable] int a = q . back (); ^ user.cpp:62:13: warning: unused variable ‘b’ [-Wunused-variable] int b = q . front (); ^ user.cpp: In function ‘ll getbuff()’: user.cpp:24:44: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buff , 1 , BUFF , stdin); ^ user.cpp:34:44: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buff , 1 , BUFF , stdin); ^ user.cpp: In function ‘int main()’: user.cpp:45:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (in , "r" , stdin); ^ user.cpp:46:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (out , "w" , stdout); ^ user.cpp:47:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buff , 1 , BUFF , stdin); ^