Compilare: user.cpp: In function ‘void bfs()’: user.cpp:19:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++){ ~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:37:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d%d",&n,&m,&xx); ^ user.cpp:39:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d",&a,&b); ^