Compilare: user.cpp: In function ‘int main()’: user.cpp:16:14: warning: unused variable ‘dir’ [-Wunused-variable] char dir; ^ user.cpp:32:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[first].size();i++) ^ user.cpp:9:32: 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:10:34: 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); ^