Compilare: main.cpp: In function 'int main()': main.cpp:47:22: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ main.cpp:51:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&x,&y); ^ main.cpp:72:16: warning: 'xx' may be used uninitialized in this function [-Wmaybe-uninitialized] dfs_euler(xx); ^