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#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>

//二叉树节点
typedef struct BitNode{
int data;
struct BitNode *lchild;
struct BitNode *rchild;
}BitNode;

BitNode *CreateBitBitNode(void)
{
BitNode *bt;
int x;
scanf("%d",&x);
if(x==-1)bt=NULL;
else{
bt = (BitNode *)malloc(sizeof(BitNode));
bt->data = x;
bt->lchild = CreateBitBitNode();
bt->rchild = CreateBitBitNode();
}
return bt;
}

//队列
typedef struct queue{
struct node *pFront;
struct node *pBehind;
int size;
}Queue;

//普通节点
typedef struct node{
struct BitNode * data;
struct node * next;
}Node;

//队列初始化
Queue * init(){
Queue * pQueue = (Queue *)malloc(sizeof(Queue));
if(pQueue == NULL){
printf("init queue failed!\n");
exit(0);
}
pQueue->pFront = NULL;
pQueue->pBehind = NULL;
pQueue->size = 0;
return pQueue;
}
//判断队列是否为空
int empty(Queue * pQueue){
if(pQueue->size == 0){
return 1;
}
return 0;
}
//队列中添加数据
void in(Queue * pQueue, BitNode * pBitNode){
Node * pNode = (Node *)malloc(sizeof(Node));
if(pNode == NULL){
printf("queue in data failed\n");
exit(0);
}
pNode->data = pBitNode;
pNode->next = NULL;
if(empty(pQueue)){
pQueue->pFront = pNode;
}else{
pQueue->pBehind->next = pNode;
}
pQueue->pBehind = pNode;
pQueue->size += 1;
}
//队列中移除并返回数据
BitNode * out(Queue * pQueue){
if(empty(pQueue)){
printf("queue is empty\n");
exit(0);
}
Node * pNode = pQueue->pFront;
pQueue->pFront = pNode->next;
pQueue->size -= 1;
BitNode * pBitNode = pNode->data;
free(pNode) ;
pNode = NULL;
return pBitNode;
}
BitNode * pop(Queue * pQueue){
if(empty(pQueue)){
printf("queue is empty!\n");
exit(0);
}
BitNode * pNode = pQueue->pBehind->data;
return pNode;
}

//二叉树按层排印
void printLevel(BitNode * pRoot){
if(pRoot == NULL){
printf("binary BitNode is empty\n");
exit(0);
}
BitNode * pBitNode;
Queue * pQueue = init();
in(pQueue, pRoot);
while(!empty(pQueue)){
pBitNode = out(pQueue);
printf("%d\n", pBitNode->data);
if(pBitNode->lchild != NULL){
in(pQueue, pBitNode->lchild);
}
if(pBitNode->rchild != NULL){
in(pQueue, pBitNode->rchild);
}
}
}

int main(){
BitNode * pRoot = NULL;
pRoot = CreateBitBitNode();
printLevel(pRoot);

return 0;
}