Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:21:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<a[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:43:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&T); ^ user.cpp:47:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:52:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&v[i]); ^ user.cpp:59:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&x,&y); ^