Compilare: user.cpp: In function ‘int main()’: user.cpp:71:10: warning: unused variable ‘enter’ [-Wunused-variable] char enter,direction; ^ user.cpp: In function ‘int get_integer()’: user.cpp:22:36: 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,dim,stdin); ^ user.cpp:31:36: 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,dim,stdin); ^ user.cpp: In function ‘char get_character()’: user.cpp:41:36: 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,dim,stdin); ^ 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,dim,stdin); ^ user.cpp: In function ‘int main()’: user.cpp:68:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zc.in","r",stdin); ^ user.cpp:69:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zc.out","w",stdout); ^ user.cpp:72:28: 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,dim,stdin); ^ user.cpp:115:22: warning: ‘add’ may be used uninitialized in this function [-Wmaybe-uninitialized] answer=answer+add-subtract; ^ user.cpp:115:35: warning: ‘subtract’ may be used uninitialized in this function [-Wmaybe-uninitialized] answer=answer+add-subtract; ^