queue

#include <stdio.h>
#include <stdlib.h>
#define MAX_SIZE 10

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

void init_queue(queuetype *q) {
	q->front = -1;
	q->rear = -1;
}

int underflow(queuetype *q) {
	return (q->rear == q->front);
}

int overflow(queuetype *q) {
	return (q->rear == MAX_SIZE - 1);
}

int queue_attach(queuetype *q, int n) {
	if (overflow(q) == 1)
		return 0;
	else 
		q->data[++(q->rear)] = n;
	return 1;
}

int dequeue(queuetype *q) {
	if (underflow(q) == 1)
		return 0;
	else
		++(q->front);
	return 1;
}

void queue_printf(queuetype *q) 
{
	for (int i = 0; i <= q->rear; i++)
	{
		if (i > q->front)
			printf("%d ", q->data[i]);
	}
}

void error_printf(queuetype *error)
{
	for (int i = 0; i <= error->rear; i++) 
	{
		if (i > error->front)
		{
			if (error->data[i] == 1) {
				printf("overflow\n");
			}
			else if (error->data[i] == 0) {
				printf("underflow\n");
			}
		}
	}
}

int main()
{
	queuetype queue;
	queuetype error;

	char check;
	int qelement;
	int datacounter;
	int pushelement;

	init_queue(&queue);
	init_queue(&error);

	scanf_s("%d", &datacounter);
	
	if (datacounter > 10)
		return 0;

	for (int i = 0; i < datacounter; i++)
	{
		scanf_s(" %c", &check);
		if (check == 'e' || check == 'E')
		{
			scanf_s("%d", &pushelement);
			if (queue_attach(&queue, pushelement) == 0)
				queue_attach(&error, 1);
		}
		else if (check == 'd' || check == 'D') 
		{
			if (dequeue(&queue) == 0) {
				queue_attach(&error, 0);
			}
		}
		else break;
	}

	error_printf(&error);
	queue_printf(&queue);

	return 0;
}