C语言队列实现

//队列演示
#include<stdio.h>
#define QUEUE_LENGTH 100
//仅能处理非负整数
struct Queue 
{
  int element[QUEUE_LENGTH];
  int head;
  int tail;
};
int QueueIn(struct Queue* p,int num)
{
  //满了
  if(p->tail>QUEUE_LENGTH-1)
  {
    return -1;
  }
  p->element[p->tail]=num;
  p->tail++;
  return 1;
}
int QueueOut(struct Queue* p)
{
  if(p->head==p->tail)
    return -1;
  return  p->element[p->head++];
}
void PrintQueue(struct Queue* p)
{
  int position=p->head;
  while(position!=p->tail)
  {
    printf("%d ",p->element[position]);
    position++;
  }
  printf("\n");
}
int main()
{
  //初始化
  struct Queue queue;
  queue.head=0;
  queue.tail=0;
  QueueIn(&queue,1);
  QueueIn(&queue,2);
  PrintQueue(&queue);
  QueueOut(&queue);
  PrintQueue(&queue);
  QueueOut(&queue);
  PrintQueue(&queue);
  QueueOut(&queue);
  PrintQueue(&queue);
  QueueIn(&queue,3);
  PrintQueue(&queue);
  return 1;
}