#include<iostream>
    #include<cstdio>
    #include<iomanip>
    #include<cassert>
    #include<string>
    #include<cmath>
    #include<iostream>
    #include<cmath>
    #include<sstream>
    #include<stdio.h>
    #include<stdlib.h>
     using namespace std;

  int const N = 20;

  struct queue
   {
    int A[N]; // N is a constant large enough to prevent false overflow
    int rear = 0;
    int front = 0;
    // initially the queue is empty
   };

  void enqueue(queue&q,int newitem) // inserts newitem into q
   {
    if(q.rear > N-1) cout << "False overflow." << endl;
    q.A[q.rear] = newitem;
    q.rear++;
   }

  bool empty(queue&q) // returns true if q is empty, false otherwise
   {
    return q.rear == q.front;
   }

  int dequeue(queue&q) // returns an item from q and deletes that item
   {
    assert(not empty(q)); // error if you try to dequeue from an empty queue
    int rslt = q.A[q.front];
    q.front++;
    return rslt;
   }

  int main()
   {
    queue q;
    enqueue(q,5);
    enqueue(q,3);
    enqueue(q,2);
    while (not empty(q)) cout << dequeue(q) << " ";
    return 1;
   }