practice6_2.c

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

#define cQ_SIZE 4

typedef char element;
typedef struct {
	element queue[cQ_SIZE];
	int front, rear;
} QueueType;

QueueType *createQueue() {
	QueueType *cQ;
	cQ = (QueueType *)malloc(sizeof(QueueType));
	cQ->front = 0;
	cQ->rear = 0;

	return cQ;
}

int isEmpty(QueueType *Q) {
	if (Q->front == Q->rear) {
		printf(" Circular Queue is empty! ");
		return 1;
	}
	else return 0;
}

int isFull(QueueType *cQ) {
	if (((cQ->rear + 1) % cQ_SIZE) == cQ->front) {
		printf(" Circular Queue is full! ");
		return 1;
	}
	else return 0;
}

void enQueue(QueueType *cQ, element item) {
	if (isFull(cQ)) return;
	else {
		cQ->rear = (cQ->rear + 1) % cQ_SIZE;
		cQ->queue[cQ->rear] = item;
	}
}

element deQueue(QueueType *cQ) {
	if (isEmpty(cQ)) exit(1);
	else {
		cQ->front = (cQ->front + 1) % cQ_SIZE;
		return cQ->queue[cQ->front];
	}
}

element peek(QueueType *cQ) {
	if (isEmpty(cQ)) exit(1);
	else return cQ->queue[(cQ->front + 1) % cQ_SIZE];
}

void printQ(QueueType *cQ) {
	int i, first, last;
	first = (cQ->front + 1) % cQ_SIZE;
	last = (cQ->rear + 1) % cQ_SIZE;
	printf(" Circular Queue : [");
	i = first;
	while(i != last){
		printf("%3c", cQ->queue[i]);
		i = (i + 1) % cQ_SIZE;
	}
	printf(" ]");
}

int main() {
	QueueType *cQ = createQueue();
	element data;
	printf("\n ******* 원형 큐 연산 ******* \n");
	printf("\n 삽입 A>>"); enQueue(cQ, 'A'); printQ(cQ);
	printf("\n 삽입 B>>"); enQueue(cQ, 'B'); printQ(cQ);
	printf("\n 삽입 C>>"); enQueue(cQ, 'C'); printQ(cQ);
	data = peek(cQ);	printf(" peek item : %c\n", data);
	printf("\n 삭제 >>");	data = deQueue(cQ);	printQ(cQ);
	printf("\t삭제 데이터 : %c", data);
	printf("\n 삭제 >>");	data = deQueue(cQ);	printQ(cQ);
	printf("\t삭제 데이터 : %c", data);
	printf("\n 삭제 >>");	data = deQueue(cQ);	printQ(cQ);
	printf("\t삭제 데이터 : %c", data);

	printf("\n 삽입 D>>"); enQueue(cQ, 'D'); printQ(cQ);
	printf("\n 삽입 E>>"); enQueue(cQ, 'E'); printQ(cQ);

	getchar();

	return 0;
}