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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;
};
/*
* 創建 隊列。
*/
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);
}
/*
* 打印隊列。
*/
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.");
}
}
/* 進隊 */
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;
}
}
}
/* 出隊 */
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);
}
摘自 angelbosj的專欄
