Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<G[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:13:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.cpp:16:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&x,&y); ^