数据结构--栈和队列 3.3.1循环队列

 

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

#define MAXSIZE 5
typedef struct Queue{
	int front;
	int rear;
	int data[MAXSIZE]; 
}Queue;

Queue * initQueue(){
	Queue * Q = (Queue*)malloc(sizeof(Queue));
	Q->front = Q->rear= 0;
	return Q; 
}

void printQueue(Queue *Q)
{
	int length = (Q->rear - Q->front + MAXSIZE)%MAXSIZE;
	int index = Q - >front;
	for(int i=0;i<length;i++)
	{
		printf("%d - >",Q->data[index]);
		index = (index + 1)%MAXSIZE;
	}
	printf("NULL\n");
}

int isFull(Queue*Q){
	if(Q->front +1 % MAXSIZE == Q->front){
		return 1;
	}
	else
	{
		return 0;
	}
}


int isEmpty(Queue * Q){
	if(Q->front == Q->rear)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}


int enQueue(Queue *Q,int data){
	if(isFull(Q))
	{
		return 0;
	}
	else
	{
		Q->data[Q->rear] = data;
		Q->rear = (Q->rear + 1)%MAXSIZE;
		return 1; 
	}
}

int deQueue(Queue * Q){
	if(isEmpty(Q)){
		return -1;
	}
	else
	{
		int data = Q->data[Q->front];
		Q->front = (Q->front +1)%MAXSIZE;
	}
}

int main()
{
	Queue* Q = initQueue();
	enQueue(Q,1);
	enQueue(Q,2);
	enQueue(Q,4);
	enQueue(Q,5);
	printQueue(Q);
	deQueue(Q);
	printQueue(Q); 
	return 0;
}