队列操作详解-优快云博客

1.#include <stdio.h>
#include <stdlib.h>
#include "SeqQueue.h"

/* run this program using the console pauser or add your own getch, system("pause") or input loop main is used to test data */

int main(int argc, char *argv[])
{
    SeqQueue* queue = SeqQueue_Create(6);
    int a[10] = {0};
    int i = 0;

    for(i=0; i<10; i++)
    {
        a[i] = i + 1;

        SeqQueue_Append(queue, a + i);
    }

    printf("Header: %d\n", *(int*)SeqQueue_Header(queue));
    printf("Length: %d\n", SeqQueue_Length(queue));
    printf("Capacity: %d\n", SeqQueue_Capacity(queue));

    while( SeqQueue_Length(queue) > 0 )
    {
        printf("Retrieve: %d\n", *(int*)SeqQueue_Retrieve(queue));
    }

    printf("\n");

    for(i=0; i<10; i++)
    {
        a[i] = i + 1;

        SeqQueue_Append(queue, a + i);

        printf("Retrieve: %d\n", *(int*)SeqQueue_Retrieve(queue));
    }

    SeqQueue_Destroy(queue);

   return 0;
}

2.#include <stdio.h>
#include <malloc.h>
#include "SeqQueue.h"
//实现队列的优化代码的实现。
typedef unsigned int TSeqQueueNode;

typedef struct _tag_SeqQueue
{
    int capacity;
    int length;
    int front;
    int rear;
    TSeqQueueNode* node;
} TSeqQueue;
//创建队列
SeqQueue* SeqQueue_Create(int capacity) // O(1)
{
    TSeqQueue* ret = NULL;

    if( capacity >= 0 )
    {
        ret = (TSeqQueue*)malloc(sizeof(TSeqQueue) + sizeof(TSeqQueueNode) * capacity);
    }
    //初始化相应变量
    if( ret != NULL )
    {
        ret->capacity = capacity;
        ret->length = 0;
        ret->front = 0;
        ret->rear = 0;
        ret->node = (TSeqQueueNode*)(ret + 1);
    }

    return ret;
}
//销毁队列
void SeqQueue_Destroy(SeqQueue* queue) // O(1)
{
    free(queue);
}
//清空队列
void SeqQueue_Clear(SeqQueue* queue) // O(1)
{
    TSeqQueue* sQueue = (TSeqQueue*)queue;

    if( sQueue != NULL )
    {
        sQueue->length = 0;
        sQueue->front = 0;
        sQueue->rear = 0;
    }
}
//入队列
int SeqQueue_Append(SeqQueue* queue, void* item) // O(1)
{
    TSeqQueue* sQueue = (TSeqQueue*)queue;
    int ret = (sQueue != NULL) && (item != NULL);

    ret = ret && (sQueue->length + 1 <= sQueue->capacity);

    if( ret )
    {
        sQueue->node[sQueue->rear] = (TSeqQueueNode)item;

        sQueue->rear = (sQueue->rear + 1) % sQueue->capacity;

        sQueue->length++;
    }

    return ret;
}
//出队列
void* SeqQueue_Retrieve(SeqQueue* queue) // O(1)
{
    TSeqQueue* sQueue = (TSeqQueue*)queue;
    void* ret = SeqQueue_Header(queue);

    if( ret != NULL )
    {
        sQueue->front = (sQueue->front + 1) % sQueue->capacity;

        sQueue->length--;
    }

    return ret;
}
//获取头元素
void* SeqQueue_Header(SeqQueue* queue) // O(1)
{
    TSeqQueue* sQueue = (TSeqQueue*)queue;
    void* ret = NULL;

    if( (sQueue != NULL) && (sQueue->length > 0) )
    {
        ret = (void*)(sQueue->node[sQueue->front]);
    }

    return ret;
}
//获取长度
int SeqQueue_Length(SeqQueue* queue) // O(1)
{
    TSeqQueue* sQueue = (TSeqQueue*)queue;
    int ret = -1;

    if( sQueue != NULL )
    {
        ret = sQueue->length;
    }

    return ret;
}
//获取队列空间
int SeqQueue_Capacity(SeqQueue* queue) // O(1)
{
    TSeqQueue* sQueue = (TSeqQueue*)queue;
    int ret = -1;

    if( sQueue != NULL )
    {
        ret = sQueue->capacity;
    }

    return ret;
}

3.#ifndef _SEQQUEUE_H_
#define _SEQQUEUE_H_

typedef void SeqQueue;

SeqQueue* SeqQueue_Create(int capacity);

void SeqQueue_Destroy(SeqQueue* queue);

void SeqQueue_Clear(SeqQueue* queue);

int SeqQueue_Append(SeqQueue* queue, void* item);

void* SeqQueue_Retrieve(SeqQueue* queue);

void* SeqQueue_Header(SeqQueue* queue);

int SeqQueue_Length(SeqQueue* queue);

int SeqQueue_Capacity(SeqQueue* queue);

#endif