Compilare: user.cpp: In function ‘void dfs(long int, long int)’: user.cpp:15:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graf[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:24:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1,"%ld",&n); ^ user.cpp:27:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f1,"%ld%ld",&x,&y); ^