queue ga kelar

#include <iostream>
#include <cstdlib>
#define MAX 6
using namespace std;

struct Queue
{
    int data[MAX];
    int head;
    int tail;
};

Queue antrian;
void create() {
    antrian.head = antrian.tail = -1;
}

int IsEmpty() {
    if (antrian.tail == -1)
    {
        return 1;
    }
    else {
        return 0;
    }
}

int IsFull() {
    if (antrian.tail == MAX-1)
    {
        return 1;
    }
    else {
        return 0;
    }
}

void Enqueue(int data) {
    system("clear");
    if (IsEmpty() == 1) {
        antrian.head = antrian.tail = 0;
        antrian.data[antrian.tail] = data;
        cout << antrian.data[antrian.tail];
    }
    else {
        system("clear");
        antrian.tail++;
        antrian.data[antrian.tail] = data;
        cout << antrian.data[antrian.tail];
    }
}

int Dequeue() {
    system("clear");
    int i;
    int e = antrian.data[antrian.head];
    for (i = antrian.head; i <= antrian.tail-1; i++) {
        antrian.data[i] = antrian.data[i+1];
    }
    antrian.tail--;
    return e;
}

void Clear() {
    system("clear");
    antrian.head = antrian.tail = -1;
    cout << "Data Clear";
}

void Tampil() {
    system("clear");
    if (IsEmpty() == 0)
    {
        for (int i = antrian.head; i <= antrian.tail; i++)
        {
            cout << antrian.data[i] << " ";
        }
    }
    else {
        cout << "Data Kosong\n";
    }
}

int main() {
    char pil;
    int data;
    create();
    do {
        system("clear");
        cout << "1. Enqueue\n"
             << "2. Dequeue\n"
             << "3. Tampil\n"
             << "4. Clear\n"
             << "5. Keluar\n\n"
             << "Masukkan pilihan : ";
        cin >> pil;

        if (pil == '1')
        {
            system("clear");
            cout << "Data : ";
            cin >> data;
            Enqueue(data);
        }
        else if (pil == '2')
        {
            if (IsEmpty() == 0)
            {
                cout << "Elemen yang keluar : " << Dequeue();
            }
            else {
                cout << "Data kosong\n";
            }
        }
        else if (pil == '3')
        {
            Tampil();
        }
        else if (pil == '4')
        {
            Clear();
        }
        else if (pil == '5')
        {
            return 0;
        }
    }
    while (pil != '5');
    return 0;
}