数据结构循环队列的基本操作-蒲公英云

数据结构循环队列的基本操作

#include <stdio.h>
#include <stdlib.h>
#define MAXQSIZE  1000
#define OK        1
#define ERROR     0 
#define OVERFLOW  -2
typedef int QElemType;
typedef struct
{
    QElemType *base;
    int front;
    int rear;
}SqQueue;
int InitQueue(SqQueue &Q)
{
    Q.base = (QElemType *)malloc(MAXQSIZE * sizeof(QElemType));
    if (!Q.base)
    {
        exit(OVERFLOW);
    }
    Q.front = Q.rear = 0;
    return OK;
}
int QueueLength(SqQueue Q)
{
    return (Q.rear - Q.front + MAXQSIZE) % MAXQSIZE;
}
int EnQueue(SqQueue &Q, QElemType e)
{
    if ((Q.rear +1) % MAXQSIZE == Q.front)
    {
        return ERROR;
    }
    Q.base[Q.rear] = e;
    Q.rear = (Q.rear +1) % MAXQSIZE;
    return OK;
}
int DeQueue (SqQueue &Q, QElemType &e)
{
    if (Q.front == Q.rear )
    {
        return ERROR;
    }
    e = Q.base [Q.front];
    Q.front = (Q.front+1) % MAXQSIZE;
    return OK;
}
int isQueueEmpty(SqQueue Q)
{//队列是否为空
    if (Q.front == Q.rear )
    {
        return 1;
    }
    return 0;
}
int isQueueFull(SqQueue Q)
{
    if ((Q.rear + 1 ) % MAXQSIZE == Q.front)
    {
        return OK;
    }
    return ERROR;
}
void Print_Q(SqQueue Q)
{
    int i;
    if ((Q.rear +1) % MAXQSIZE == Q.front)
    {
        return;
    }
    for (i=0; i<QueueLength(Q); i++)
    {
        printf("%d ",Q.base[Q.front+i]);
    }
    printf("\n");
}
int GetHead(SqQueue &Q, QElemType &e)
{
    if (Q.front == Q.rear )
    {
        return ERROR;
    }
    e = Q.base[Q.front];
    return OK;
}
int main()
{
    SqQueue Q;
    int i,n;
    InitQueue(Q);
    scanf("%d",&n);
    for (i=1; i<=n; i++)
    {
        EnQueue(Q,i);
    }
    Print_Q(Q);
    DeQueue(Q,n);
    DeQueue(Q,n);
    DeQueue(Q,n);
    DeQueue(Q,n);
    Print_Q(Q);
    GetHead(Q,i);
    printf("%d\n",i);
    return 0;
}