Compilare: user.cpp: In function ‘int nextInt()’: user.cpp:25:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] for (; !isDigit[*head]; ++head); ^ user.cpp:26:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] for (; isDigit[*head]; ++head) ^ user.cpp: At global scope: user.cpp:55:37: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) void putNumber(int x) { ^~~~~~~~~ user.cpp:23:36: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) int nextInt() { ^~~~~~~ user.cpp: In function ‘int main()’: user.cpp:77:32: 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); ^ user.cpp:78:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.out", "w", stdout); ^