队列

1.循环队列

#include<stdio.h>
#define MAXSIZE 10
#define TRUE 1
#define FALSE 0
typedef struct
{
    int data[MAXSIZE];
    int front;
    int rear;
}SqQueue;
int InitQueue(SqQueue *Q);
int QueueLength(SqQueue *Q);
int EnQueue(SqQueue *Q,int m);
int DeQueue(SqQueue *Q,int *e);
int main()
{
    SqQueue queue;
    int t;
    InitQueue(&queue);
    for(int i=0;i<MAXSIZE-1;++i)
    {
        EnQueue(&queue,i);
    }
    DeQueue(&queue,&t);
    printf("%d\n",t);
    return 0;
}

int InitQueue(SqQueue *Q)
{
    Q->front=0;
    Q->rear=0;
    return TRUE;
}
int QueueLength(SqQueue *Q)
{
    return (Q->rear-Q->front+MAXSIZE)%MAXSIZE;
}
int EnQueue(SqQueue *Q,int m)
{
    if((Q->rear+1)%MAXSIZE==Q->front)
        return FALSE;
    Q->data[Q->rear]=m;
    Q->rear=(Q->rear+1)%MAXSIZE;
    return TRUE;
}
int DeQueue(SqQueue *Q,int *e)
{
    if(Q->front==Q->rear)
        return FALSE;
    *e=Q->data[Q->front];
    Q->front=(Q->front+1)%MAXSIZE;
    return TRUE;
}

2.队列的链式存储结构

#include<stdio.h>
#include<stdlib.h>
#define TRUE 1
#define FALSE 0
typedef struct QNODE
{
    int data;
    QNODE *next;
}QNode,*QueuePtr;
typedef struct
{
    QueuePtr front;
    QueuePtr rear;
}LinkQueue;
int InitQueue(LinkQueue *Q);
int    EnQueue(LinkQueue *Q,int m);
int DeQueue(LinkQueue *Q,int *e);   //error C2018: unknown character '0xa3' 因为分号用的是中文状态下的

int main()
{
    LinkQueue queue;
    QNode *p;
    p=(QNode*)malloc(sizeof(QNode));
    p->next=NULL;
    queue.front=p;
    queue.rear=p;
    int e;
    for(int i=0;i<10;++i)
    {
        EnQueue(&queue,i);
    }
    DeQueue(&queue,&e);
    printf("%d\n",e);
    return 0;
}

int    EnQueue(LinkQueue *Q,int m)
{
    QNode *p;
    p=(QNode*)malloc(sizeof(QNode));
    p->data=m;
    p->next=NULL;
    Q->rear->next=p;
    Q->rear=p;
    return TRUE;
}
int DeQueue(LinkQueue *Q,int *e)
{
    if(Q->front==Q->rear)
        return FALSE;
    QNode *p;
    p=Q->front->next;
    *e=p->data;
    Q->front->next=p->next;
    if(Q->rear==p)      //如果对头是队尾，则删除后将rear指向头结点
        Q->rear=Q->front;
    free(p);
    return TRUE;
}