循环队列的实现

#include
#include

#define MAXSIZE 10

typedef struct CQNode
{
    int data[MAXSIZE];
    int front;
    int end;
} CQNode, *CQList;

void InitCQL ( CQList CQ )
{
    if ( CQ == NULL )
    {
        CQ = ( CQList ) malloc ( sizeof ( CQNode ) );
    }

    CQ->front = 0;
    CQ->end = 0;
}

void InsertCQL ( CQList CQ, int value )
{
    if ( ( CQ->end - CQ->front + MAXSIZE + 1 ) % ( MAXSIZE ) == 0 )
    {
        printf ( "Queue is full" );
        printf ( "%d is not insert\n", value );
        return;
    }
    else
    {
        CQ->data[CQ->end] = value;
        CQ->end++;
        CQ->end = CQ->end % MAXSIZE;
    }
}

int DeleteCQL ( CQList CQ )
{
    int res;

    if ( cq->end == cq->front )
    {
        printf ( "queue is empty\n" );
        return -1;
    }
    else
    {
        res = CQ->data[CQ->front];
        CQ->front++;
        CQ->front = CQ->front % MAXSIZE;
    }

    return res;
}

void Print ( CQList CQ )
{
    int i;
    i = CQ->front;

    while ( i != CQ->end )
    {
        printf ( "%d,", CQ->data[i] );
        i++;

        if ( i == MAXSIZE )
            i = 0;
    }

    printf ( "\n" );
}

int main()
{
    int i, val;
    CQList cl;

    cl = ( CQList ) malloc ( sizeof ( CQNode ) );
    InitCQL ( cl );

    for ( i = 1; i < 12; i++ )
    {
        InsertCQL ( cl, i * 3 + 3 );
    }

    Print ( cl );
    getchar();

    for ( i = 1; i < 7; i++ )
    {
        val = DeleteCQL ( cl );

        if ( val != -1 )
            printf ( "%d is deleted\n", val );
    }

    getchar();

    for ( i = 4; i < 12; i++ )
    {
        InsertCQL ( cl, i * 6 );
    }

    Print ( cl );
    getchar();

    return 0;
}