使用链表实现队列------《数据结构与算法分析-C语言描述》

#ifndef _QUE_LINK_H_
#define _QUE_LINK_H_

struct que_record;
typedef struct que_record* que;
struct link_node;
typedef struct link_node* node;
typedef int elementType;

int IsFull(que q);
int IsEmpty(que q);
que creatQue(int max_num);
void makeEmpty(que q);
void enque(elementType x,que q);
void deque(que q);
elementType front_que(que q);
elementType front_deque(que q);
void dispose_que(que q);

struct que_record
{
node front;
node rear;
int size;
};

struct link_node
{
elementType data;
struct link_node* next;
};

#endif

#include <stdio.h>

#include <stdlib.h>

#include "que_link.h"

#define MAXSIZE 10

int IsFull(que q)
{
return q->size == MAXSIZE;
}

int IsEmpty(que q)
{
return q->size == 0;
}

que creatQue(int max_num)
{
que q;
q = (que)malloc(sizeof(struct que_record));
q->size = 0;
q->front = q->rear = (node)malloc(sizeof(struct link_node));
q->front->next = q->rear->next = NULL;
return q;
}

void makeEmpty(que q)
{
if(NULL == q)
{
printf("the que is not exsit \n");
exit(-1);
}

while(q->size)
deque(q);
}

void deque(que q)
{

node ptr = NULL;

ptr = q->front->next;
free(q->front);
q->front = ptr;
q->size--;

if(q->size == 0)
{
//q->front->next = q->rear->next = NULL;
q->front = q->rear = NULL;
}
}

void enque(elementType x, que q)
{
if(q)
{
if(IsFull(q))
{
printf("the que is full \n");
exit(-4);
}

printf("the enque x is %d\n",x);
static int init_flag = 0;
if(!init_flag)
{
q->rear->data = x;
q->rear->next = NULL;
q->size++;
init_flag = 1;
}
else
{
node ptr=(node )malloc(sizeof(struct link_node));
ptr->data = x;
q->rear->next = ptr;
q->rear = q->rear->next;
q->rear->next = NULL;
q->size++;
}
}
}

elementType front_que(que q)
{
if(q)
{
if(IsEmpty(q))
{
printf("the que is empty\n");
exit(-5);
}

return q->front->data;
}
}

elementType front_deque(que q)
{
if(q)
{
if(IsEmpty(q))
{
printf("the que is empty,so can't deque\n");
exit(-6);
}

elementType x;
x = q->front->data;
deque(q);
return x;
}
}

void dispose_que(que q)
{
if(q)
{
makeEmpty(q);
free(q);
}
}

int main(int argc,char *argv[])
{
elementType val;
int i = 0;
que q;
q = creatQue(10);
while(i++ < 10 )
{
printf("now ,please input the value:\n");
scanf("%d",&val);
printf("the val is %d\n",val);
enque(val,q);
printf("the q size is %d\n",q->size);
if(val == 0)
break;
}

while(q->size)
{
val = front_deque(q);
printf("the val is %d\n",val);
sleep(1);
}

dispose_que(q);

return 0;
}

hangma@ubuntu:~/test/test/protest/que_test$ gcc  que_link.c -o que_link
hangma@ubuntu:~/test/test/protest/que_test$ ./que_link
now ,please input the value:
1
the val is 1
the enque x is 1
the q size is 1
now ,please input the value:
2
the val is 2
the enque x is 2
the q size is 2
now ,please input the value:
3
the val is 3
the enque x is 3
the q size is 3
now ,please input the value:
4
the val is 4
the enque x is 4
the q size is 4
now ,please input the value:
5
the val is 5
the enque x is 5
the q size is 5
now ,please input the value:
6
the val is 6
the enque x is 6
the q size is 6
now ,please input the value:
7
the val is 7
the enque x is 7
the q size is 7
now ,please input the value:
8
the val is 8
the enque x is 8
the q size is 8
now ,please input the value:
9
the val is 9
the enque x is 9
the q size is 9
now ,please input the value:
10
the val is 10
the enque x is 10
the q size is 10
the val is 1
the val is 2
the val is 3
the val is 4
the val is 5
the val is 6
the val is 7
the val is 8
the val is 9
the val is 10