C语言队列动态数组实现

 

/*
 * Queue.h
 *
 *  Created on: 2011-10-7
 *      Author: Admin
 */

#ifndef QUEUE_H_
#define QUEUE_H_
#include <stdio.h>
#include <stdlib.h>

/* the data type that contained in the queue */
typedef int QueueData;

typedef struct _queue{

    size_t length;      /* queue length */
    size_t capacity;    /* queue capacity */
    size_t index;       /* get data index */
    size_t push_index;  /* insert index */
    QueueData *data;    /* the data that queue contain */
}Queue, *pQueue;

/* initialize queue */
void queue_init(pQueue* ptr, size_t size);

/* free memory which the queue own*/
void queue_destroy(pQueue* ptr);

/* add data to queue */
int queue_push(pQueue ptr, QueueData val);

/* dequeue */
QueueData queue_pop(pQueue ptr);

/* get data at front of the queue */
QueueData queue_top(pQueue ptr);

/* return the size of queue */
size_t queue_size(pQueue ptr);

#endif /* QUEUE_H_ */


/*
 * Queue.c
 *
 *  Created on: 2011-10-7
 *      Author: Admin
 */
#include <stdio.h>
#include <stdlib.h>
#include "Queue.h"

/* initialize queue */
void queue_init(pQueue* ptr, size_t size){

    *ptr = (pQueue)malloc(sizeof(Queue));
    if ((*ptr) == NULL){
        exit(1);
    }
    (*ptr)->capacity = size;
    (*ptr)->length = 0;
    (*ptr)->index = 0;
    (*ptr)->push_index = 0;
    (*ptr)->data = (QueueData*)malloc(sizeof(QueueData) * size);

    if ((*ptr)->data == NULL){
        exit(1);
    }
}

/* free memory which the queue own*/
void queue_destroy(pQueue* ptr){
    free((*ptr)->data);
    (*ptr)->data = NULL;
    free((*ptr));
    (*ptr) = NULL;
}

/* add data to queue */
int queue_push(pQueue ptr, QueueData val){
    if (ptr->length >= ptr->capacity){
        return 0;
    }
    ptr->push_index = (ptr->push_index % ptr->capacity) + 1;
    ptr->data[ptr->push_index - 1] = val;
    ptr->length += 1;
    return 1;
}

/* dequeue */
QueueData queue_pop(pQueue ptr){
    if (ptr->length <= 0 ){
        exit(1);
    }
    ptr->length -= 1;
    ptr->index = ((ptr->index) % ptr->capacity) + 1;
    return ptr->data[ptr->index - 1];

}

/* get data at front of the queue */
QueueData queue_top(pQueue ptr){

    return ptr->data[ptr->index];

}

/* return the size of queue */
size_t queue_size(pQueue ptr){

    return ptr->length;
}