using System; using static System.Console; using System.Linq; using System.Collections.Generic; class Program { static int NN => int.Parse(ReadLine()); static int[] NList => ReadLine().Split().Select(int.Parse).ToArray(); static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray(); public static void Main() { Solve(); } static void Solve() { var n = NN; var p = NList; var plist = new Pair[n]; var ntree = new AvlTree<int>(); var tree = new AvlTree<Pair>(); for (var i = 0; i < n; ++i) { ntree.Insert(i); plist[p[i] - 1] = new Pair(p[i] - 1, i); tree.Insert(plist[p[i] - 1]); } var q = new List<int>(n); while (ntree.GetCount() > 1) { var pos = ntree.ElementAt(0); var pidx = 0; tree.LowerBound(plist[pos], ref pidx); if (pidx + 1 < tree.GetCount()) { q.Add(plist[pos].Id + 1); tree.Delete(plist[pos]); var next = tree.ElementAt(pidx); q.Add(next.Id + 1); tree.Delete(next); ntree.Delete(pos); ntree.Delete(next.Id); } else { pos = ntree.ElementAt(1); tree.LowerBound(plist[pos], ref pidx); q.Add(plist[pos].Id + 1); tree.Delete(plist[pos]); var next = tree.ElementAt(pidx); q.Add(next.Id + 1); tree.Delete(next); ntree.Delete(pos); ntree.Delete(next.Id); } } WriteLine(string.Join(" ", q)); } class Pair : IComparable<Pair> { public int Id; public int Pos; public Pair(int id, int pos) { Id = id; Pos = pos; } public int CompareTo(Pair other) { return Pos.CompareTo(other.Pos); } } public class AvlTree<T> where T: IComparable<T> { private class Node<U> where U: IComparable<U> { public U Value; public Node<U> Lc = null; public Node<U> Rc = null; public int Height; public int Count; public int CCount; public Node(int height, U value) { Height = height; Count = 1; CCount = 1; Value = value; } } private Node<T> root = null; static int GetHeight(Node<T> t) { return t == null ? 0 : t.Height; } static int GetCount(Node<T> t) { return t == null ? 0 : t.Count; } static int GetBalance(Node<T> t) { return GetHeight(t.Lc) - GetHeight(t.Rc); } static void Recalc(Node<T> t) { if (t == null) return; t.Height = 1 + Math.Max(GetHeight(t.Lc), GetHeight(t.Rc)); t.Count = t.CCount + GetCount(t.Lc) + GetCount(t.Rc); } static Node<T> RotateLeft(Node<T> t) { Node<T> u = t.Rc; Node<T> t2 = u.Lc; u.Lc = t; t.Rc = t2; Recalc(t); Recalc(u); return u; } static Node<T> RotateRight(Node<T> t) { Node<T> u = t.Lc; Node<T> t2 = u.Rc; u.Rc = t; t.Lc = t2; Recalc(t); Recalc(u); return u; } static Node<T> RotateLR(Node<T> t) { t.Lc = RotateLeft(t.Lc); return RotateRight(t); } static Node<T> RotateRL(Node<T> t) { t.Rc = RotateRight(t.Rc); return RotateLeft(t); } static Node<T> BalanceLeft(Node<T> t) { if (GetBalance(t) > 1) { if (GetBalance(t.Lc) < 0) t = RotateLR(t); else t = RotateRight(t); } Recalc(t); return t; } static Node<T> BalanceRight(Node<T> t) { if (GetBalance(t) < -1) { if (GetBalance(t.Rc) > 0) t = RotateRL(t); else t = RotateLeft(t); } Recalc(t); return t; } /// <summary>valueを挿入する</summary> public void Insert(T value) { root = Insert(root, value); } Node<T> Insert(Node<T> cur, T value) { if (cur == null) { return new Node<T>(1, value); } var d = value.CompareTo(cur.Value); if (d < 0) { cur.Lc = Insert(cur.Lc, value); return BalanceLeft(cur); } else if (d > 0) { cur.Rc = Insert(cur.Rc, value); return BalanceRight(cur); } else { ++cur.CCount; Recalc(cur); return cur; } } /// <summary>valueを削除する 存在しない場合はなにもしない</summary> public void Delete(T value) { root = Delete(root, value); } Node<T> Delete(Node<T> cur, T value) { if (cur == null) return null; var d = value.CompareTo(cur.Value); if (d < 0) { cur.Lc = Delete(cur.Lc, value); return BalanceRight(cur); } else if (d > 0) { cur.Rc = Delete(cur.Rc, value); return BalanceLeft(cur); } else { --cur.CCount; if (cur.CCount == 0) { if (cur.Lc != null) { Node<T> del = null; var max = DeleteMax(cur.Lc, ref del); cur.Lc = max; cur.Value = del.Value; cur.CCount = del.CCount; return BalanceRight(cur); } else { return cur.Rc; } } else { Recalc(cur); return cur; } } } Node<T> DeleteMax(Node<T> t, ref Node<T> del) { if (t.Rc == null) { del = t; return t.Lc; } else { var max = DeleteMax(t.Rc, ref del); t.Rc = max; return BalanceLeft(t); } } /// <summary>小さいほうからpos番目の要素を取得する</summary> public T ElementAt(int pos) { if (pos < 0 || pos >= GetCount(root)) return default; var t = ElementAt(root, pos); return t.Value; } /// <summary>小さいほうからpos番目の要素を取得する</summary> public T ElementAt(int pos, T defaultValue) { if (pos < 0 || pos >= GetCount(root)) return defaultValue; return ElementAt(pos); } Node<T> ElementAt(Node<T> cur, int pos) { if (pos < GetCount(cur.Lc)) return ElementAt(cur.Lc, pos); if (pos < GetCount(cur.Lc) + cur.CCount) return cur; if (pos < cur.Count) return ElementAt(cur.Rc, pos - GetCount(cur.Lc) - cur.CCount); return null; } public void Debug() { if (root == null) return; Console.WriteLine($"root val:{root.Value}, CCount:{root.CCount}, Count:{root.Count}"); Debug(root.Value, root.Lc); Debug(root.Value, root.Rc); } void Debug(T pval, Node<T> cur) { if (cur == null) return; Console.WriteLine($"{pval} -> val:{cur.Value}, CCount:{cur.CCount}, Count:{cur.Count}"); Debug(cur.Value, cur.Lc); Debug(cur.Value, cur.Rc); } /// <summary>value以上でもっとも小さい値とその場所を返却する</summary> public T LowerBound(T value, ref int index) { var cur = root; T ans = default; var add = 0; index = GetCount(root); while (cur != null) { if (value.CompareTo(cur.Value) <= 0) { ans = cur.Value; index = add + GetCount(cur.Lc); cur = cur.Lc; } else { add += GetCount(cur.Lc) + cur.CCount; cur = cur.Rc; } } return ans; } /// <summary>要素の個数を求める</summary> public int GetCount() { return GetCount(root); } } }