public class Queue_withArray {

static class Queue{

static int arr[];

static int size;

static int rear = -1;

Queue(int n){

arr = new int[n];

this.size = n;

}

public static boolean isEmpty(){

return rear == -1;

}

//enqueue

public static void add(int data){

if(rear == size-1){

System.out.println("full queue");

return;

}

rear++;

arr[rear] = data;

}

public static int remove(){

if(isEmpty()){

System.out.println("empty queue");

return -1;

}

int front = arr[0];

for (int i = 0; i < rear; i++) {

arr[i] = arr[i+1];

}

rear--;

return front;

}

public static int peek(){

if(isEmpty()){

System.out.println("empty queue");

return -1;

}

return arr[0];

}

}

public static void main(String[] args) {

Queue q = new Queue(5);

q.add(1);

q.add(2);

q.add(3);

q.add(4);

q.remove(); // to remove 1

while(!q.isEmpty()){

System.out.println(q.peek());

q.remove();

}

}

}