数据结构---队列链表c实现

#include <stdio.h>
#include <stdlib.h>
typedef int elemType;
#define maxsize 100
struct Quenue {
 elemType date;
    struct Quenue *next;
};
struct QuenueLK {
 struct Quenue *front;
 struct Quenue *rear;
};
void InitQueue(struct QuenueLK *s)
{
 s->front = s->rear = NULL;
 return ;
}
void DestroyQueue(struct QuenueLK *s)
{
 struct Quenue *p = s->front;
 if(p!=NULL)
 {
  s->front = s->front->next;
  free(p);
  p = s->front ;
 }
 s->rear = NULL;
 return ;
}
int QueueEmpty(struct QuenueLK *s)
{
 if(s->front!=NULL)
 {
  return 1;
 }
 else 
  return 0;
}
int QueueLength(struct QuenueLK *s)
{
 int sum = 0;
 struct QuenueLK *p =s;
 while(p->rear!=NULL)
 {
  p->rear = p->rear->next;
 }

 return sum;
}
elemType GetHead(struct QuenueLK *s)
{
 if(s->rear!=NULL)
 {
  return s->front->date;
    }
 else
  return 0;
}
void EnQueue(struct QuenueLK *s,elemType x)
{
 struct Quenue *newp;
 newp = malloc(sizeof(struct Quenue));
 if(newp == NULL)
 {
  printf("内存分配失败!");
  exit(1);
 }
 newp->date = x;
 newp->next = NULL;
 if(s->rear == NULL)
 {
  s->front = s->rear = newp;
 }
 else 
  s->rear = s->rear->next = newp;
 return ;
}
elemType DeQueue(struct QuenueLK *s)
{
 struct Quenue *p;
 elemType  x = 0;
 if(s->front == NULL)
 {
  printf("队列为空,无法删除!");
  exit(1);
 }
 x = s->front->date;
 p = s->front;
 s->front = p->next;
 if(s->front == NULL)
 {
  s->rear = NULL;
 }
 free(p);
 return x;
}
void traverse(struct QuenueLK s)
{
 struct QuenueLK *p = &s;
 printf("从队首到队尾依次输出:");
 while(p->front!=NULL)
 {
  printf("%d ",p->front->date);
  p->front = p->front->next;
 }
 return ;
}

void main()
{
 elemType x = 0;
 int i = 0;
 struct QuenueLK s;
 while(1)
 {
      printf("1->初始化链式队列\n");
     printf("2->销毁队列\n");
     printf("3->判空队列\n");
     printf("4->队列长度\n");
     printf("5->读取队首元素\n");
  printf("6->入列\n");
  printf("7->出列\n");
  printf("8->遍历队列\n");
     printf("清选择操作:");
  scanf("%d",&i);
  switch(i)
  { 
      case 1:
     printf("初始化链式队列");
     InitQueue(&s);
     break;
      case 2:
     printf("销毁队列:");
     DestroyQueue(&s);
     break;
      case 3:
     if(QueueEmpty(&s))
     {
       printf("队列非空!");
    getchar();
    getchar();
    break;
     }
     else
    printf("队列为空!");
       getchar();
    getchar();
             break;
       case 4:
     printf("队列长度为%d:",QueueLength(&s));
     getchar();
     getchar();
     break;
    case 5:
     printf("队首元素为%d:",GetHead(&s));
           getchar();
     getchar();
     break;
       case 6:
     printf("请输入入列元素:");
     scanf("%d",&x);
     EnQueue(&s,x);
           getchar();
     getchar();
     break;
    case 7:
     printf("出列元素为:%d",DeQueue(&s));
           getchar();
     getchar();
     break;
    case 8:
     printf("遍历队列!\n");
     traverse(s);
           getchar();
     getchar();
     break;
  }
  system("cls"); 
 }
      

}