怎么求二叉树每层上的节点数？

void levelorder(BiTree T)
{
    BiTree Queue[maxsize],p;
    int front,rear,last,first,level;
    front=rear=first=0;
    last=level=1;
    if(T)
    {
        Queue[rear++]=T;
        while(front<rear)
        {
            p=Queue[front++];
            if(p->lchild)
                Queue[rear++]=p->lchild;
            if(p->rchild)
                Queue[rear++]=p->rchild;
            if(front==last)
            {
                printf("level%2d:%d\n",level,last-first);
                level++;
                last=rear;
                first=front;
            }
        }
    }
    else
        printf("None");
}