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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_QUEUE_SIZE 10
typedef int elem_t;
typedef struct _queue queue_t;
struct _queue
{
elem_t data[MAX_QUEUE_SIZE];
int front,rear,size;
};
int QueueIsFull(queue_t *q)
{
return ((q->rear+1)%MAX_QUEUE_SIZE == q->front);
}
int QueueIsEmpty(queue_t *q)
{
return (q->rear == q->front);
}
int InQueue(queue_t *q,elem_t d)
{
if (QueueIsFull(q))
{
printf("Queue is full");
exit(1);
}
q->data[q->rear] = d;
q->rear = (q->rear+1) % MAX_QUEUE_SIZE;
q->size++;
return 0;
}
elem_t OutQueue(queue_t *q)
{
elem_t retval;
if (QueueIsEmpty(q))
{
printf("Queue is empty");
exit(1);
}
retval = q->data[q->front];
q->front = (q->front+1) % MAX_QUEUE_SIZE;
q->size--;
return retval;
}
elem_t ViewQueue(queue_t *q)
{
if (QueueIsEmpty(q))
{
printf("Queue is empty");
return -1;
}
return q->data[q->front];
}
int InitQueue(queue_t *q)
{
memset(&q->data,0,MAX_QUEUE_SIZE * sizeof(elem_t));
q->rear = q->front = q->size =0;
return 0;
}
int TraverseQueue(queue_t *q)
{
int front,rear;
printf("\n");
for( front = q->front,rear = q->rear
; front != rear
; front = (front+1)%MAX_QUEUE_SIZE)
{
printf("%d,",q->data[front]);
}
return 0;
}
int QueueFreeSize(queue_t *q)
{
return MAX_QUEUE_SIZE-1-q->size;
}
int main(int argc,char *argv[])
{
queue_t queue;
elem_t retval;
int i;
InitQueue(&queue);
printf("\nQueue size : %d",QueueFreeSize(&queue));
for (i=0;i<9;i++)
InQueue(&queue,i*2);
printf("\nQueue size : %d",QueueFreeSize(&queue));
retval = OutQueue(&queue);
retval = OutQueue(&queue);
retval = OutQueue(&queue);
printf("\nQueue size : %d",QueueFreeSize(&queue));
InQueue(&queue,55);
InQueue(&queue,66);
printf("\nQueue size : %d",QueueFreeSize(&queue));
TraverseQueue(&queue);
return 0;
}
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