Compilare: user.cpp: In function ‘int BFS(int)’: user.cpp:72:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < D[x].size() ; i ++ ){ ^ user.cpp: In function ‘void Read()’: user.cpp:86:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%d" , &V , &n , &m ); ^ user.cpp:89:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d\n%d\n%s\n" , &x , &y , s ); ^ user.cpp: In function ‘int main()’: user.cpp:129:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( IN , "r" , stdin ); ^ user.cpp:130:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ( OUT , "w" , stdout ); ^