/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:7:7: warning: unused variable 'i' [-Wunused-variable]
   int i,j,flag=1,temp,k;
       ^
/in/foo.cc:7:9: warning: unused variable 'j' [-Wunused-variable]
   int i,j,flag=1,temp,k;
         ^
/in/foo.cc:7:11: warning: variable 'flag' set but not used [-Wunused-but-set-variable]
   int i,j,flag=1,temp,k;
           ^~~~