프린터_queue

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX_QUEUE_SIZE 10000

typedef int element;
typedef struct {
	element data[MAX_QUEUE_SIZE];
	int front, rear;
}queuetype;

void init_queue(queuetype *q) {
	q->front = q->rear = 0;
}

int full(queuetype *q) {
	return ((q->rear + 1) % MAX_QUEUE_SIZE == q->front);
}

int empty(queuetype *q) {
	if (q->front == q->rear)
		return 1;
	else
		return 0;
}

void push(queuetype *q, element item) {
	if (full(q)) return;
	q->rear = (q->rear + 1) % MAX_QUEUE_SIZE;
	q->data[q->rear] = item;
}

int pop(queuetype *q) {
	if (empty(q)) 
	{
		printf("-1\n");
		return 0;
	}
	printf("%d\n", q->data[q->front + 1]);
	q->front = (q->front + 1) % MAX_QUEUE_SIZE;
}

void size(queuetype *q) {
	printf("%d\n", (q->rear - q->front) % MAX_QUEUE_SIZE);
}

int front(queuetype *q) {
	if (empty(q)) {
		printf("-1\n");
		return 0;
	}
	printf("%d\n", q->data[q->front + 1]);
}

int back(queuetype *q) {
	if (empty(q)) {
		printf("-1\n");
		return 0;
	}
	printf("%d\n", q->data[q->rear]);
}

int main()
{
	queuetype queue;
	char str[10];
	int N = 0;
	init_queue(&queue);

	scanf_s("%d ", &N);

	for (int i = 0; i < N; i++)
	{
		scanf_s("%s", str, 10);

		if (strcmp(str,"push") == 0) 
		{
			element num = 0;
			scanf_s("%d", &num);
			push(&queue, num);
		}
		else if (strcmp(str, "pop") == 0) {
			pop(&queue);
		}
		else if (strcmp(str, "size") == 0) {
			size(&queue);
		}
		else if (strcmp(str, "empty") == 0)	{
			if (empty(&queue) == 1)
				printf("1\n");
			else
				printf("0\n");
		}
		else if (strcmp(str, "front") == 0) {
			front(&queue);
		}
		else if (strcmp(str, "back") == 0) {
			back(&queue);
		}
	}
	return 0;
}