Compilare: user.cpp: In function ‘void bfs()’: user.cpp:39:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k=0;k<C.size();k++) ^ user.cpp: In function ‘int main()’: user.cpp:68:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasik.in","r",stdin); ^ user.cpp:69:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ahocorasik.out","w",stdout); ^