队列的实现(FIFO、链表)

#include<stdio.h>#include<stdlib.h>#include<assert.h>typedefstruct queue_list{      struct queue_list *next;      int value;}queue_list;static queue_list *front=NULL;static queue_list *rear=NULL;void insert(int value){   if(front==NULL)   {      front=(queue_list*)malloc(sizeof(queue_list));      rear=front;      front->value=value;      rear->value=value;   }   else   {      queue_list *new_list;      new_list=(queue_list*)malloc(sizeof(queue_list));      new_list->value=value;      rear->next=new_list;      rear=new_list;   }}void delete(){   assert(front!=NULL);   queue_list *new_list;   new_list=front;   front=front->next;   free(new_list);}int first(){   assert(front!=NULL);   return front->value;}int main(){   insert(5);   insert(4);   insert(3);   printf("%d\n",first());   delete();   printf("%d\n",first());   delete();   printf("%d\n",first());   delete();   printf("%d\n",first());   return 0;}