循环队列(数组实现)

 

 

 

#include <stdio.h>
#include <stdlib.h>

#define false 0
#define true 1

typedef int ElementType;
typedef int Position;
typedef int bool;
typedef struct QNode *PtrToQNode;
struct QNode
{
   ElementType *Data;
   Position Front,Rear;
   int MaxSize;
};
typedef PtrToQNode Queue;

Queue CreateQueue(int MaxSize);   //创建一个最大长度为MaxSize的空队列
bool IsFull(Queue Q);   //判断队列是否已满
bool IsEmpty(Queue Q);  //判断队列是否为空
bool AddQ(Queue Q, ElementType X);    //入队
ElementType DeleteQ(Queue Q);         //出队



Queue CreateQueue(int MaxSize)
{
    Queue Q = (Queue)malloc(sizeof(struct QNode));
    Q->Data = (ElementType *)malloc(MaxSize*sizeof(ElementType));
    Q->Front = Q->Rear = 0;
    Q->MaxSize = MaxSize;
    return Q;
}

bool IsFull(Queue Q)
{
    return ((Q->Rear+1) % (Q->MaxSize)) == Q->Front;
}

bool IsEmpty(Queue Q)
{
    return Q->Front == Q->Rear;
}

bool AddQ(Queue Q, ElementType X)
{
    if(IsFull(Q))
    {
        printf("队列已满，无法入队！\n");
        return false;
    }
    Q->Rear = (Q->Rear+1)%(Q->MaxSize);
    Q->Data[Q->Rear] = X;
    return true;
}

ElementType DeleteQ(Queue Q)
{
    if(IsEmpty(Q))
    {
        printf("队列为空，无法出队！\n");
        return false;
    }
    Q->Front = (Q->Front+1)%(Q->MaxSize);
    return Q->Data[Q->Front];
}