Compilare: user.cpp: In function ‘void BFS()’: user.cpp:20:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i<a[aux].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:42:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d%d",&n,&m,&x,&y); ^ user.cpp:45:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&x1,&y1); ^