Problem:
Score : 300 points

Problem Statement

You are given an integer sequence of length n, a_1, ..., a_n.
Let us consider performing the following n operations on an empty sequence b.

The i-th operation is as follows:

Append a_i to the end of b.

Reverse the order of the elements in b.

Find the sequence b obtained after these n operations.

Constraints

1 \leq n \leq 2\times 10^5

0 \leq a_i \leq 10^9

n and a_i are integers.

Input

Input is given from Standard Input in the following format:

n
a_1 a_2 ... a_n

Output

Print n integers in a line with spaces in between.
The i-th integer should be b_i.

Sample Input 1

4
1 2 3 4

Sample Output 1

4 2 1 3

After step 1 of the first operation, b becomes: 1.

After step 2 of the first operation, b becomes: 1.

After step 1 of the second operation, b becomes: 1, 2.

After step 2 of the second operation, b becomes: 2, 1.

After step 1 of the third operation, b becomes: 2, 1, 3.

After step 2 of the third operation, b becomes: 3, 1, 2.

After step 1 of the fourth operation, b becomes: 3, 1, 2, 4.

After step 2 of the fourth operation, b becomes: 4, 2, 1, 3.

Thus, the answer is 4 2 1 3.

Sample Input 2

3
1 2 3

Sample Output 2

3 1 2

As shown above in Sample Output 1, b becomes 3, 1, 2 after step 2 of the third operation. Thus, the answer is 3 1 2.

Sample Input 3

1
1000000000

Sample Output 3

1000000000

Sample Input 4

6
0 6 7 6 7 0

Sample Output 4

0 6 6 0 7 7

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using static System.Math;
using MethodImplAttribute = System.Runtime.CompilerServices.MethodImplAttribute;
using MethodImplOptions = System.Runtime.CompilerServices.MethodImplOptions;

public static class P
{
    public static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        var a = Console.ReadLine().Split().Select(int.Parse).ToArray();
        Deque<int> deque = new Deque<int>();
        for (int i = 0; i < a.Length; i++)
        {
            if (((i ^ n) & 1) == 0) deque.PushBack(a[i]);
            else deque.PushFront(a[i]);
        }

        Console.WriteLine(string.Join(" ", deque));
    }
}


class Deque<T> : IEnumerable<T>
{
    public int Count;
    T[] data; int FrontInd, BackInd;
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public Deque() { data = new T[1 << 16]; FrontInd = 0; BackInd = data.Length - 1; Count = 0; }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public Deque(T[] elem)
    {
        int s = elem.Length; s |= s >> 1; s |= s >> 2; s |= s >> 4; s |= s >> 8; s |= s >> 16;
        data = new T[++s]; elem.CopyTo(data, 0);
        FrontInd = 0; BackInd = elem.Length - 1; Count = elem.Length;
    }

    public T Front
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        get { ValidateNoEmpty(); return data[FrontInd]; }
    }
    public T Back
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        get { ValidateNoEmpty(); return data[BackInd]; }
    }

    public T this[int index]
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        get { if (index >= Count) throw new Exception(); return data[FrontInd + index & data.Length - 1]; }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        set { if (index >= Count) throw new Exception(); data[FrontInd + index & data.Length - 1] = value; }
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public void PushFront(T elem) { if (Count == data.Length) Extend(data.Length << 1); Count++; data[FrontInd = (FrontInd - 1) & data.Length - 1] = elem; }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public T PopFront() { var res = Front; FrontInd = (FrontInd + 1) & data.Length - 1; Count--; return res; }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public void PushBack(T elem) { if (Count == data.Length) Extend(data.Length << 1); Count++; data[BackInd = (BackInd + 1) & data.Length - 1] = elem; }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public T PopBack() { var res = Back; BackInd = (BackInd - 1) & data.Length - 1; Count--; return res; }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private void Extend(int newSize)
    {
        T[] newData = new T[newSize];
        if (0 < Count)
        {
            if (FrontInd <= BackInd) Array.Copy(data, FrontInd, newData, 0, Count);
            else
            {
                Array.Copy(data, FrontInd, newData, 0, data.Length - FrontInd);
                Array.Copy(data, 0, newData, data.Length - FrontInd, BackInd + 1);
            }
        }
        data = newData; FrontInd = 0; BackInd = Count - 1;
    }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private void ValidateNoEmpty() { if (Count == 0) throw new Exception(); }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public IEnumerator<T> GetEnumerator() { for (int i = FrontInd; i != BackInd; i = i + 1 & data.Length - 1) yield return data[i]; yield return data[BackInd]; }
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
}