链式队列的两种实现方式（C语言）

实现方式一

1、头文件LinkQueue.h

#include <stdio.h>
typedef struct Node
{
    struct Node* next;
}Node;

typedef struct LinkQueue
{
    Node* front;
    Node* rear;
    int length;
}LinkQueue;

void InitQueue(LinkQueue*);
int QueueEmpty(LinkQueue*);
int QueueLength(LinkQueue*);
void GetFront(LinkQueue*, Node**);
void EnQueue(LinkQueue*, Node*);
void DeQueue(LinkQueue*, Node**);
void ClearQueue(LinkQueue*);

2、相关操作函数文件LinkQueue.c

#include <stdio.h>
#include "LinkQueue.h"

void InitQueue(LinkQueue* lq)
{
    lq->front = NULL;
    lq->rear = NULL;
    lq->length = 0;
}

int QueueEmpty(LinkQueue* lq)
{
    if(lq->length == 0)
        return 1;

    return 0;
}

int QueueLength(LinkQueue* lq)
{
    return lq->length;
}

void GetFront(LinkQueue* lq, Node** e)
{
    if(lq->length == 0)
    {
        printf("空队列！\n");
        return;
    }

    *e = lq->front;
}

void EnQueue(LinkQueue* lq, Node* e)
{
    if(lq->length == 0)
    {
        lq->front = lq->rear = e;
    }
    else
    {
        lq->rear->next = e;
        lq->rear = lq->rear->next;
    }

    lq->length++;
}

void DeQueue(LinkQueue* lq, Node** e)
{
    if(lq->length == 0)
    {
        printf("空队列！\n");
        return;
    }

    *e = lq->front;
    lq->front = lq->front->next;
    lq->length--;
    if(lq->length == 0)
    {
        lq->rear = NULL;
    }
}

void ClearQueue(LinkQueue* lq)
{
    while(lq->length)
    {
        Node* tmp;
        DeQueue(lq, (Node**)&tmp);
    }
}

3、主函数测试文件main.c

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

typedef struct stu
{
    Node p;
    int id;
    int age;
}student;

int main()
{
    LinkQueue lq;
    InitQueue(&lq);
    student s[10];
    int i = 0;
    for(i = 0; i < 10; i++)
    {
        s[i].id = i;
        s[i].age = i + 20;
        EnQueue(&lq, &s[i].p);
    }

    printf("当前队列长度为：%d\n", QueueLength(&lq));

    while(!QueueEmpty(&lq))
    {
        Node* tmp;
        GetFront(&lq, (Node**)&tmp);
        student* tmp1 = (student*)tmp;
        printf("当前队头元素值为：id = %d, age = %d\n", tmp1->id, tmp1->age);
        DeQueue(&lq, (Node**)&tmp);
        tmp1 = (student*)tmp;
        printf("当前出队元素值为：id = %d, age = %d\n", tmp1->id, tmp1->age);
        printf("\n");

    }
    return 0;
}

实现方式二

1、头文件LinkQueue.h

#include <stdio.h>

typedef struct Node
{
    struct Node* next;
}Node;

typedef struct QueueNode
{
    Node P;
    void* data;
}QueueNode;

typedef struct LinkQueue
{
    int length;
    QueueNode* front;
    QueueNode* rear;
}LinkQueue;

void InitQueue(LinkQueue*);
int QueueEmpty(LinkQueue*);
int QueueLength(LinkQueue*);
void GetFront(LinkQueue*, void**);
void EnQueue(LinkQueue*, void*);
void DeQueue(LinkQueue*, void**);
void ClearQueue(LinkQueue*);

2、相关操作函数main.c

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

void InitQueue(LinkQueue* lq)
{
    lq->length = 0;
    lq->front = NULL;
    lq->rear = NULL;
}

int QueueEmpty(LinkQueue* lq)
{
    if(lq->length == 0)
        return 1;
    return 0;
}

int QueueLength(LinkQueue* lq)
{
    return lq->length;
}

void GetFront(LinkQueue* lq, void** e)
{
    if(lq->length == 0)
    {
        printf("空队列！\n");
        return;
    }

    *e = lq->front->data;
}

void EnQueue(LinkQueue* lq, void* e)
{
    QueueNode* pNew = (QueueNode*)malloc(sizeof(QueueNode));
    pNew->data = e;

    if(lq->length == 0)
    {
        lq->front = lq->rear = pNew;
    }
    else
    {
        lq->rear->P.next = &pNew->P;
        lq->rear = pNew;
    }
    lq->length++;
}

void DeQueue(LinkQueue* lq, void** e)
{
    if(lq->length == 0)
    {
        printf("空队列！\n");
        return;
    }

    QueueNode* pDel;
    pDel = lq->front;
    *e = pDel->data;
    lq->front = (QueueNode*)pDel->P.next;
    free(pDel);

    lq->length--;
    if(lq->length == 0)
    {
        lq->rear = NULL;
    }
}
void ClearQueue(LinkQueue* lq)
{
    while(lq->length)
    {
        void* tmp;
        DeQueue(lq, (void**)&tmp);
    }
}

3、主函数main.c

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

typedef struct stu
{
    int id;
    int age;
}student;

int main()
{
    LinkQueue lq;
    InitQueue(&lq);
    student s[10];

    int i = 0;
    for(i = 0; i < 10; i++)
    {
        s[i].id = i;
        s[i].age = i + 20;
        EnQueue(&lq, &s[i]);
    }

    printf("当前队列的长度为：%d\n", QueueLength(&lq));

    while(!QueueEmpty(&lq))
    {
        student* tmp;
        GetFront(&lq, (void**)&tmp);
        printf("当前队头元素值为：id = %d, age = %d\n", tmp->id, tmp->age);

        DeQueue(&lq, (void**)&tmp);
        printf("当前出队元素值为：id = %d, age = %d\n", tmp->id, tmp->age);
        printf("\n");
    }
    printf("当前队列的长度为：%d\n", QueueLength(&lq));

    EnQueue(&lq, &s[0]);
    ClearQueue(&lq);
    printf("当前队列的长度为：%d\n", QueueLength(&lq));

    return 0;
}