#include \
  <queue>
   void
LevelOrder
 (   node
 *      n
 )
 {    std
 :: queue
 <   node
 *
 >      q
 ;      q
 .   push
 (      n
 )
 ;  while
 (
 !      q
 .  empty
 (
        )
 )
 { auto c
 =      q
 .  front
 (
 )
 ;     if
 (      c
 )
 { printf
 (  "%d "
 ,      c
 ->  data
 )
 ;      q
 .   push
 (      c
 ->  left
 )
 ;      q
 .   push
 (      c
 -> right
 )
        ;
 }      q
 .    pop
  (
       )
   ;
      }
    }