《数据结构与算法分析》学习笔记（五）——队ADT

#define QMAXSIZE 100

typedef int Position;
typedef int QElement;

typedef struct queue
{
    QElement Els[QMAXSIZE];
    Position head,tail;
}Queue;

void QCreate(Queue &Q)
{
    Q.head = Q.tail = 0;
}

void Enqueue(QElement e,Queue &Q)
{
    if((Q.tail + 1) % QMAXSIZE == Q.head)
    {
        printf("Queue Full");
    }
    else
    {
        Q.Els[Q.tail] = e;
        Q.tail = (Q.tail + 1)% QMAXSIZE;
    }
}

void Dequeue(QElement &e,Queue &Q)
{
    if(Q.head == Q.tail)
    {
        printf("Queue Empty");
    }
    else
    {
        e = Q.Els[Q.head];
        Q.head = (Q.head + 1) % QMAXSIZE;
    }
}

QElement Head(Queue Q)
{
    if(Q.tail == Q.head )
    {
        printf("Queue Empty");
    }
    else
    {
        return Q.Els[Q.head];
    }
}

bool Empty(Queue Q)
{
    return(Q.tail == Q.head );
}

bool Full(Queue Q)
{
    return((Q.tail + 1) % QMAXSIZE == Q.head );
}