【数据结构】3.6链式队列（附实现代码）

链式队列实现代码如下

#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>

#define QElemType int

typedef struct QNode{
    QElemType data;
    struct QNode * next;
}QNode, * QueuePtr;

typedef struct{
    QueuePtr front;
    QueuePtr rear;
}LinkQueue;

void InitQueue(LinkQueue &Q);
bool EnQueue(LinkQueue &Q, QElemType e);
bool DeQueue(LinkQueue &Q, QElemType &e);
void Traverse(LinkQueue Q);
void DestroyQueue(LinkQueue &Q);
void ClearQueue(LinkQueue &Q);


int main (void)
{
    QElemType e;
    LinkQueue Q;
    InitQueue(Q);
    EnQueue(Q , 2);
    EnQueue(Q , 3);
    EnQueue(Q , 4);
    EnQueue(Q , 4);
    if(DeQueue(Q , e))
    {
        printf("DeQueue succeed!The element deleted is %d\n",e);
    }
    Traverse(Q);
//  DestroyQueue(Q);
    ClearQueue(Q) ;
    EnQueue(Q , 2);
    EnQueue(Q , 3);
    EnQueue(Q , 5);
    Traverse(Q);


    printf("=======Ending========\n");
    return 0;
}

void InitQueue(LinkQueue &Q)
{
    //构造一个队列Q 
    Q.front = Q.rear = (QueuePtr)malloc(sizeof(QNode)); //队列空时Q.front == Q.rear 
    if (!Q.front)                                       //存储分配失败 
        exit(-1);
    Q.front->next = NULL;
}

bool EnQueue(LinkQueue &Q, QElemType e)
//插入元素e为Q新的队尾元素 
{
    QueuePtr p = (QueuePtr)malloc(sizeof(QNode));
    if(!p)                                          //除非内存满了，否则不会存在队满的问题 
        return false;
    p->data = e;
    p->next = NULL;
    Q.rear->next = p;
    Q.rear = p;
    return true;
}

bool DeQueue(LinkQueue &Q, QElemType &e)
    //若队列不为空则删除Q的对头元素，用e返回其值 
{
    if(Q.front == Q.rear)
        return false;
    QueuePtr p = Q.front->next;
    e = p->data;
    Q.front->next = p->next;
    if(Q.rear == p)
        Q.rear = Q.front;
    free(p);
    return true;
}

void Traverse(LinkQueue Q)
{
    QueuePtr p = Q.front->next;
    while(p != NULL)                            
        {
            printf("%d\t",p->data);
            p = p->next;
        }
    printf("\n");
}

void DestroyQueue(LinkQueue &Q) 
{
    while(Q.front)
    {
        int i = 0;
        Q.rear = Q.front->next;
        free(Q.front);
        Q.front = Q.rear;
    }

}

void ClearQueue(LinkQueue &Q)
{
    QueuePtr p = Q.front->next;
    while(p)
    { 
        int i = 0;
        Q.rear = p->next;
        free(p);
        p = Q.rear;
    }
    Q.rear = Q.front;
}