Compilare: main.cpp: In function 'void dfs(int)': main.cpp:8:9: warning: unused variable 'j' [-Wunused-variable] int j; ^ main.cpp: In function 'int main()': main.cpp:40:16: warning: variable 'fout' set but not used [-Wunused-but-set-variable] FILE *fin,*fout; ^~~~ main.cpp:44:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&n,&m); ^ main.cpp:46:33: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&a,&b); ^