数据结构——基本数据结构之队列

循环队列
用一组抵制连续的存储单元依次存放从队头到队尾的元素
另外两个指针front和rear分别指示队列头元素和尾元素的位置

queue.h


#ifndef _QUEUE_H


#define _QUEUE_H




#define MaxQSize 100


typedef int ElemType;






typedef struct SqQueue...{


ElemType *base;


int front;


int rear;


}Queue;




int InitQueue(Queue **q);


int DestroyQueue(Queue **q);


int ClearQueue(Queue **q);


int QueueEmpty(Queue *q);


int QueueLength(Queue *q);


int GetHead(Queue *q, ElemType *e);


int EnQueue(Queue **q, ElemType e);


int DeQueue(Queue **q, ElemType *e);




#endif

queue.c


#include <stdio.h>


#include <stdlib.h>


#include "queue.h"




int InitQueue(Queue **q)




...{


(*q)->base = (ElemType *)malloc(MaxQSize * sizeof(ElemType));


if(!(*q)->base)


return 0;


(*q)->front = 0;


(*q)->rear = 0;




return 1;


}




int QueueEmpty(Queue *q)




...{


if(q->rear == q->front)


return 1;


else


return 0;


}




int QueueLength(Queue *q)




...{


return (q->rear - q->front + MaxQSize) % MaxQSize;


}




int EnQueue(Queue **q, ElemType e)




...{


if(((*q)->rear + 1) % MaxQSize == (*q)->front)


return 0;


(*q)->base[(*q)->rear] = e;


(*q)->rear = ((*q)->rear + 1) % MaxQSize;




return 1;


}




int DeQueue(Queue **q, ElemType *e)




...{


if((*q)->rear == (*q)->front)


return 0;


*e = (*q)->base[(*q)->front];


(*q)->front = ((*q)->front + 1) % MaxQSize;




return 1;


}

QueueMain.c


#include <stdio.h>


#include "queue.h"




int main(int argc, char **argv)




...{


ElemType e;


Queue *q;




q = (Queue *)malloc(sizeof(Queue));


InitQueue(&q);


while((e = getchar()) != '#')




...{


EnQueue(&q, e);


}


while(!QueueEmpty(q))




...{


DeQueue(&q, &e);


printf("%c ", e);


}




return 0;


}