queue.c

离散事件模拟程序

// queue.c
#include "queue.h"
#include "malloc.h"
#include "string.h"


bool InitQueue(LinkQueue *Q)
{
    Q->front = Q->rear = (QueuePtr)malloc(sizeof(QNode));
    if (!Q->front)
        return false;
    Q->front->next = NULL;
    return true;
}

bool DestroyQueue(LinkQueue *Q)
{
    while (Q->front)
    {
        Q->rear = Q->front->next;
        free(Q->front);
        Q->front = Q->rear;
    }
    return true;
}

bool ClearQueue(LinkQueue *Q)
{
    DestroyQueue(Q);
    return InitQueue(Q);
}

bool QueueEmpty(LinkQueue Q)
{
    return (Q.front == Q.rear);
}

int  QueueLength(LinkQueue Q)
{
    return Q.rear-Q.front;
}

bool GetHead(LinkQueue Q, QElemType  *pdata)
{
    if (QueueEmpty(Q))return false;
    *pdata = Q.front->next->data;
    return true;
}

bool EnQueue(LinkQueue *Q, QElemType data)
{
    QueuePtr p;
    p = (QueuePtr)malloc(sizeof(QNode));
    if (!p)
        return false;
    p->data = data;
    p->next = NULL;
    Q->rear->next = p;
    Q->rear = p;
    return true;
}

bool DeQueue(LinkQueue *Q, QElemType *pdata)
{
    // 头结点
    QueuePtr p = Q->front->next;
    if (QueueEmpty(*Q))return false;
    Q->front->next = p->next;
    *pdata = p->data;
    // 不要疏忽了这个可能
    if (p==Q->rear)
        Q->rear = Q->front;
    free(p);
    return true;
}

bool QueueTraverse(LinkQueue *Q, bool (*visit)(QElemType *))
{
    // 头结点
    QueuePtr p = Q->front->next;
    while(p)
    {
        if (!visit(&p->data))
            return false;
        p = p->next;
    }
    return true;
}