queuefrontback

// Online C++ compiler to run C++ program online
#include <iostream>
using namespace std;

int queue[100111];

int front = 1;
int back = 1;


void insert(int x) {
    queue[back] = x;
    back++;
}

void pop() {
    queue[front] = 0;
    front++;
}

int getFront() {
    
    return queue[front];
}

void show() {
    
    for (int i = front; i < back; i++) {
        cout << queue[i] << " ";
    }
    cout << endl;
}

bool isEmpty() {
    
    return (front == back);
}
int main() {
    // Write C++ code here

    insert(2);
    insert(3);
    insert(4);
    insert(5);
    while (!isEmpty()) {
        pop();
    }
    
    insert(6);
    insert(7);
    show();
    return 0;
}