/in/foo.cc: In function 'void print_by_2(int)':
/in/foo.cc:11:16: error: 'itoa' was not declared in this scope
  itoa(val,buf,2);
                ^
/in/foo.cc: In function 'int press(int, int)':
/in/foo.cc:17:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i=1;i<=G[bnt][0];++i)
  ^~~
/in/foo.cc:19:6: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
      return val;
      ^~~~~~