队列

队列：

栈先进后出，队列先进先出

队列：

#include<stdio.h>

#include<stdlib.h>

typedef char ElementType;

typedef struct node

{

ElementType data;

struct node *next;

}Node;

 

typedef struct list

{

Node *first;

Node *last;

int count;

}List;

 

//创建一个空队列

List * CreateQueue(void)

{

List *l = (List*)malloc(sizeof(List));

l->first = l->last = NULL;

l->count = 0;

 

return l;

}

 

//入对

void EnQueue(List *l,ElementType ch)

{

if(l == NULL)

return ;

Node *p = (Node *)malloc(sizeof(Node));

p->data = ch;

p->next = NULL;

if(l->first == NULL)

{

l->first = l->last = p;

}

else

{

l->last->next = p;

l->last = p;

}

l->count++;

}

 

//出队

Node *DeQueue(List *l)

{

if(l == NULL)

return NULL;

Node *p = l->first;

if(l->first == l->last)

{

l->first = l->last = NULL;

}

else

{

l->first = p->next;

p->next = NULL;

}

l->count--;

return p;

}

 

//判断队列空

int QueueEmpty(List *l)

{

if(l)

{

if(l->first == NULL)

return 1;

else

return 0;

}

}

int main(int argc,char *argv[])

{

List *l = CreateQueue();

ElementType x;

while(1)

{

scanf("%c",&x);

if(x == '#')

break;

EnQueue(l,x);

}

Node *p = NULL;

 

while(QueueEmpty(l) == 0)

{

p = DeQueue(l);

printf("%c\t",p->data);

free(p);

}

p = NULL;

printf("\n");

 

return 0;

}