用数组去实现队列（c）

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#include <stdio.h>
#include <stdlib.h>

struct QueueRecord;
typedef struct QueueRecord *Queue;

#define MinQueueSize (5)

struct QueueRecord
{
    int Capacity;
    int Front;
    int Rear;
    int Size;
    int *Array;
};

/*
* 创建队列。
*/
Queue CreateQueue(int capacity)
{
    Queue queue;
    queue = (Queue)malloc(sizeof(Queue));
    if (queue == NULL)
    {
        printf("out of space!!!\n");
    }
    queue->Array = (int *)malloc(capacity * sizeof(int));
    if (queue->Array == NULL)
    {
        printf("out of space!!!\n");
    }
    queue->Size = 0;
    queue->Rear = -1;
    queue->Front = 0;

    return queue;
}

/*
* if full ,return 0; else return 1;
*/
int IsFull(Queue queue, int capacity)
{
    return (queue->Size < capacity);
}

/* if null return 1. else 0 */
int IsEmpty(Queue queue)
{
    return (queue->Size == 0);
}

/*
* 打印队列。
*/
int ShowQueue(Queue queue, int capacity)
{
    int i;

    printf("queue->Front = %d\n", queue->Front);
    printf("queue->Rear = %d\n", queue->Rear);
    if (!IsEmpty(queue))
    {
        for (i = queue->Front; i <= queue->Rear; i++)
            {
                if (i < queue->Rear)
                {
                    printf("%d, ", queue->Array[i]);
                }
                else
                {
                    printf("%d ", queue->Array[i]);
                }

            }
    }
    else
    {
        printf("oh, sorry. it is empty.");
    }

}
/* 进队 */
void Enqueue(Queue queue, int a, int capacity)
{
    queue->Rear++;
    queue->Array[queue->Rear] = a;
    queue->Size++;

    if (IsFull(queue, capacity))
    {
        if (queue->Rear == capacity)
        {
            queue->Rear = 0;
        }

    }

}

/* 出队 */
void Dequeue(Queue queue, int capacity)
{
    queue->Front++;
    queue->Size--;

    if (IsFull(queue, capacity))
    {
        if (queue->Front== capacity)
        {
            queue->Front = 0;
        }

    }
}

int main(void)
{
    Queue queue;
    int capacity = 10;
    if (capacity < MinQueueSize)
    {
        printf("it is too small.\n");
    }

    queue = CreateQueue(capacity);
    Enqueue(queue, 1, capacity);
    Enqueue(queue, 2, capacity);
    Enqueue(queue, 3, capacity);
    Enqueue(queue, 4, capacity);
    Enqueue(queue, 5, capacity);
    Enqueue(queue, 6, capacity);
    Dequeue(queue, capacity);
    Enqueue(queue, 12, capacity);
    //Enqueue(queue, 3, capacity);
    ShowQueue(queue, capacity);

}

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