/in/foo.cc: In function 'int main()':
/in/foo.cc:55:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(rg i=1;i<=n;i++)
  ^~~
/in/foo.cc:57:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
   memset(head,-1,sizeof(head));
   ^~~~~~
/in/foo.cc:68:16: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
     else printf("%d\n",ans[k]);
          ~~~~~~^~~~~~~~~~~~~~~