Compilare: user.cpp: In function ‘int get_int()’: user.cpp:26:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(; !isDigit[buffer[head]]; ++head); ^ user.cpp:28:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(; isDigit[buffer[head]]; ++head) ^ user.cpp: At global scope: user.cpp:35:37: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) void put_int(int x) ^~~~~~~ user.cpp:22:36: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) int get_int() ^~~~~~~ user.cpp: In function ‘int main()’: user.cpp:97:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.in", "r", stdin); ^