使用数组实现队列----《数据结构与算法分析---C语言描述》

一、h文件：my_que.h

#ifndef  _MY_QUE_H_
#define  _MY_QUE_H_
struct QueRecord;
typedef struct QueRecord* queue;

typedef  int element_type;

int IsEmpty(queue q);
int IsFull(queue q);
queue creat_que(int max_element);
void make_empty(queue q);
void enqueue(element_type x,queue q);
element_type front_que(queue q);
void dequeue(queue q);
element_type front_deque(queue q);
void dispose_que(queue q);

#define mini_que 5

struct QueRecord
{
    int capacity;
    int size;
    int front;
    int rear;
    element_type *array;
};

#endif

二、c文件：my_que.c

hangma@ubuntu:~/test/test/protest/que_test$ cat my_que.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "my_que.h"

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

int IsFull(queue q)
{
    return q->size == q->capacity;
}

queue creat_que(int max_element)
{
    queue q;

    if(max_element < mini_que)
    {
printf("the size of que is too small\n");
exit(-2);
    }

    q = (queue)malloc(sizeof(struct QueRecord));
    if(q == NULL)
    {
printf("can't alloca memory\n");
        exit(-1);
    }

    q->array = (element_type *)malloc(max_element * sizeof(element_type));
    if(q->array == NULL)
    {
printf("can't alloca the mem\n");
exit(-1);
    }
    q->capacity = max_element;

    make_empty(q);
    return q;
}

void make_empty(queue q)
{
    if(q != NULL)
    {
q->size = 0;
        q->front = 1;
q->rear = 0;
    }
}

int IsQueEnd(int value,queue q)
{
    if( ++value == q->capacity)
    return 0;
    else
return value;
}

void enqueue(element_type x,queue q)
{
    if(q == NULL)
    {
printf("the que is not exsit\n");
exit(-2);
    }

    if(IsFull(q))
    {
printf("the que is full\n");
exit(-2);
    }

    q->size++;
    q->rear = IsQueEnd(q->rear,q);
    q->array[q->rear] = x;
}

element_type front_que(queue q)
{
    if(IsEmpty(q))
    {
printf("the que is empty\n");
exit(-3);
    }

    return q->array[q->front];
}

void dequeue(queue q)
{
    if(IsEmpty(q))
    {
printf("the que is empty\n");
exit(-4);
    }

    q->size--;
    q->front = IsQueEnd(q->front,q);
}

element_type front_deque(queue q)
{
    if(IsEmpty(q))
    {
printf("the que is empty");
exit(-5);
    }

    q->size--;
    int front = q->front;
    q->front = IsQueEnd(q->front,q);
    return q->array[front];
}

void dispose_que(queue q)
{
    if(q)
    {
if(q->array)
    {
   free(q->array);
}
free(q);
    }
}

int main(int argc ,char *argv[])
{
    element_type val;
    int i = 0;
    queue q;

    q = creat_que(10);
    while( ++i <= 10 )
    {
printf("now ,please input the value:\n");
scanf("%d",&val);
printf("the val is %d\n",val);
enqueue(val,q);
printf("the q size is %d\n",q->size);
    } 

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

    dispose_que(q);
    return 0;
}

三、打印输出：

hangma@ubuntu:~/test/test/protest/que_test$ ./my_que
now ,please input the value:
1
the val is 1
the q size is 1
now ,please input the value:
2
the val is 2
the q size is 2
now ,please input the value:
3
the val is 3
the q size is 3
now ,please input the value:
4
the val is 4
the q size is 4
now ,please input the value:
5
the val is 5
the q size is 5
now ,please input the value:
6
the val is 6
the q size is 6
now ,please input the value:
7
the val is 7
the q size is 7
now ,please input the value:
8
the val is 8
the q size is 8
now ,please input the value:
9
the val is 9
the q size is 9
now ,please input the value:
10
the val 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