結果

問題 No.2337 Equidistant
ユーザー yupiteru_kunyupiteru_kun
提出日時 2023-06-02 21:38:55
言語 C#
(.NET 8.0.203)
結果
AC  
実行時間 3,541 ms / 4,000 ms
コード長 39,883 bytes
コンパイル時間 9,455 ms
コンパイル使用メモリ 167,572 KB
実行使用メモリ 232,916 KB
最終ジャッジ日時 2024-06-08 22:32:16
合計ジャッジ時間 58,496 ms
ジャッジサーバーID
(参考情報)
judge3 / judge4
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 73 ms
29,824 KB
testcase_01 AC 70 ms
29,696 KB
testcase_02 AC 72 ms
29,824 KB
testcase_03 AC 76 ms
29,952 KB
testcase_04 AC 74 ms
29,824 KB
testcase_05 AC 74 ms
29,696 KB
testcase_06 AC 105 ms
35,072 KB
testcase_07 AC 102 ms
34,944 KB
testcase_08 AC 102 ms
34,816 KB
testcase_09 AC 101 ms
34,944 KB
testcase_10 AC 104 ms
35,072 KB
testcase_11 AC 2,618 ms
227,348 KB
testcase_12 AC 2,416 ms
227,140 KB
testcase_13 AC 2,419 ms
227,144 KB
testcase_14 AC 2,387 ms
227,200 KB
testcase_15 AC 2,424 ms
227,276 KB
testcase_16 AC 2,463 ms
227,160 KB
testcase_17 AC 2,418 ms
227,196 KB
testcase_18 AC 2,395 ms
227,080 KB
testcase_19 AC 2,430 ms
227,196 KB
testcase_20 AC 2,392 ms
227,368 KB
testcase_21 AC 2,878 ms
207,724 KB
testcase_22 AC 2,129 ms
232,108 KB
testcase_23 AC 2,195 ms
232,468 KB
testcase_24 AC 3,541 ms
207,804 KB
testcase_25 AC 2,239 ms
232,776 KB
testcase_26 AC 3,434 ms
207,944 KB
testcase_27 AC 2,356 ms
232,916 KB
testcase_28 AC 2,314 ms
232,888 KB
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コンパイルメッセージ
  復元対象のプロジェクトを決定しています...
  /home/judge/data/code/main.csproj を復元しました (91 ms)。
MSBuild のバージョン 17.9.6+a4ecab324 (.NET)
  main -> /home/judge/data/code/bin/Release/net8.0/main.dll
  main -> /home/judge/data/code/bin/Release/net8.0/publish/

ソースコード

diff #

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using static System.Math;
using System.Text;
using System.Threading;
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using Library;

namespace Program
{
    public static class ProblemD
    {
        static bool SAIKI = false;
        static public int numberOfRandomCases = 0;
        static public void MakeTestCase(List<string> _input, List<string> _output, ref Func<string[], bool> _outputChecker)
        {
        }
        static public void Solve()
        {
            var N = NN;
            var Q = NN;
            var AB = Repeat(0, N - 1).Select(_ => new { A = NN - 1, B = NN - 1 }).ToArray();
            var ST = Repeat(0, Q).Select(_ => new { S = NN - 1, T = NN - 1 }).ToArray();
            var tree = new LIB_Tree(N);
            foreach (var item in AB)
            {
                tree.AddPath(item.A, item.B);
            }
            var dp = tree.LIB_ReRooting<long>()
                .VertexToValue(e => 1)
                .MergeSubtrees((s, t) => s + t)
                .MergeVertexAndSubtree((v, s) => v + s)
                .Build();
            var containsVtx = new bool[N];
            var deq = new LIB_Deque<long>();
            var mo = tree.LIB_OfflinePathQuery(0).SetAddRightEdgeMethod((a, b) =>
            {
                var idx = a;
                if (idx == -1 || containsVtx[idx]) idx = b;
                deq.PushBack(idx);
                containsVtx[idx] = true;
            }).SetAddLeftEdgeMethod((a, b) =>
            {
                var idx = a;
                if (idx == -1 || containsVtx[idx]) idx = b;
                deq.PushFront(idx);
                containsVtx[idx] = true;
            }).SetDeleteRightEdgeMethod((a, b) =>
            {
                containsVtx[deq.PopBack()] = false;
            }).SetDeleteLeftEdgeMethod((a, b) =>
            {
                containsVtx[deq.PopFront()] = false;
            });
            foreach (var item in ST)
            {
                mo.AddQuery(item.S, item.T);
            }
            var answer = new long[Q];
            mo.SetChecker(ansIdx =>
            {
                if (deq.Count % 2 == 0) answer[ansIdx] = 0;
                else
                {
                    var left = deq[deq.Count / 2 - 1];
                    var center = deq[deq.Count / 2];
                    var right = deq[deq.Count / 2 + 1];
                    answer[ansIdx] = N - dp[left, center] - dp[right, center];
                }
            });
            mo.Execute();
            foreach (var item in answer)
            {
                Console.WriteLine(item);
            }
        }
        class Printer : StreamWriter
        {
            public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
            public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { base.AutoFlush = false; }
            public Printer(Stream stream, Encoding encoding) : base(stream, encoding) { base.AutoFlush = false; }
        }
        static LIB_FastIO fastio = new LIB_FastIODebug();
        static string[] args;
        static public void Main(string[] args_t) { args = args_t; if (args_t.Length == 0) { fastio = new LIB_FastIO(); Console.SetOut(new Printer(Console.OpenStandardOutput())); } if (SAIKI) { var t = new Thread(Solve, 134217728); t.Start(); t.Join(); } else Solve(); Console.Out.Flush(); }
        static long NN => fastio.Long();
        static double ND => fastio.Double();
        static string NS => fastio.Scan();
        static long[] NNList(long N) => Repeat(0, N).Select(_ => NN).ToArray();
        static double[] NDList(long N) => Repeat(0, N).Select(_ => ND).ToArray();
        static string[] NSList(long N) => Repeat(0, N).Select(_ => NS).ToArray();
        static long Count<T>(this IEnumerable<T> x, Func<T, bool> pred) => Enumerable.Count(x, pred);
        static IEnumerable<T> Repeat<T>(T v, long n) => Enumerable.Repeat<T>(v, (int)n);
        static IEnumerable<int> Range(long s, long c) => Enumerable.Range((int)s, (int)c);
        static IOrderedEnumerable<T> OrderByRand<T>(this IEnumerable<T> x) => Enumerable.OrderBy(x, _ => xorshift);
        static IOrderedEnumerable<T> OrderBy<T>(this IEnumerable<T> x) => Enumerable.OrderBy(x.OrderByRand(), e => e);
        static IOrderedEnumerable<T1> OrderBy<T1, T2>(this IEnumerable<T1> x, Func<T1, T2> selector) => Enumerable.OrderBy(x.OrderByRand(), selector);
        static IOrderedEnumerable<T> OrderByDescending<T>(this IEnumerable<T> x) => Enumerable.OrderByDescending(x.OrderByRand(), e => e);
        static IOrderedEnumerable<T1> OrderByDescending<T1, T2>(this IEnumerable<T1> x, Func<T1, T2> selector) => Enumerable.OrderByDescending(x.OrderByRand(), selector);
        static IOrderedEnumerable<string> OrderBy(this IEnumerable<string> x) => x.OrderByRand().OrderBy(e => e, StringComparer.OrdinalIgnoreCase);
        static IOrderedEnumerable<T> OrderBy<T>(this IEnumerable<T> x, Func<T, string> selector) => x.OrderByRand().OrderBy(selector, StringComparer.OrdinalIgnoreCase);
        static IOrderedEnumerable<string> OrderByDescending(this IEnumerable<string> x) => x.OrderByRand().OrderByDescending(e => e, StringComparer.OrdinalIgnoreCase);
        static IOrderedEnumerable<T> OrderByDescending<T>(this IEnumerable<T> x, Func<T, string> selector) => x.OrderByRand().OrderByDescending(selector, StringComparer.OrdinalIgnoreCase);
        static string Join<T>(this IEnumerable<T> x, string separator = "") => string.Join(separator, x);
        static uint xorshift { get { _xsi.MoveNext(); return _xsi.Current; } }
        static IEnumerator<uint> _xsi = _xsc();
        static IEnumerator<uint> _xsc() { uint x = 123456789, y = 362436069, z = 521288629, w = (uint)(DateTime.Now.Ticks & 0xffffffff); while (true) { var t = x ^ (x << 11); x = y; y = z; z = w; w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)); yield return w; } }
        static bool Chmax<T>(this ref T lhs, T rhs) where T : struct, IComparable<T> { if (lhs.CompareTo(rhs) < 0) { lhs = rhs; return true; } return false; }
        static bool Chmin<T>(this ref T lhs, T rhs) where T : struct, IComparable<T> { if (lhs.CompareTo(rhs) > 0) { lhs = rhs; return true; } return false; }
        static void Fill<T>(this T[] array, T value) => array.AsSpan().Fill(value);
        static void Fill<T>(this T[,] array, T value) => MemoryMarshal.CreateSpan(ref array[0, 0], array.Length).Fill(value);
        static void Fill<T>(this T[,,] array, T value) => MemoryMarshal.CreateSpan(ref array[0, 0, 0], array.Length).Fill(value);
        static void Fill<T>(this T[,,,] array, T value) => MemoryMarshal.CreateSpan(ref array[0, 0, 0, 0], array.Length).Fill(value);
    }
}
namespace Library {
    class LIB_SlidingWindowAggregation<T>
    {
        T[][] list;
        T[][] agg;
        int[] size;
        Func<T, T, T> fun;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_SlidingWindowAggregation(IEnumerable<T> ary, Func<T, T, T> f)
        {
            list = new T[2][]; agg = new T[2][]; size = new int[2];
            fun = f;
            list[0] = new T[16]; agg[0] = new T[16]; size[0] = 0;
            if (ary.Any())
            {
                var temp = ary.ToArray();
                size[1] = temp.Length;
                list[1] = new T[size[1]];
                agg[1] = new T[size[1]];
                for (var i = 0; i < list[1].Length; i++)
                {
                    list[1][i] = temp[i];
                    if (i == 0) agg[1][i] = temp[i];
                    else agg[1][i] = fun(agg[1][i - 1], temp[i]);
                }
            }
            else
            {
                list[1] = new T[16]; agg[1] = new T[16]; size[1] = 0;
            }
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_SlidingWindowAggregation(Func<T, T, T> f) : this(new T[0], f) { }
        public int Count => size[0] + size[1];
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Clear()
        {
            size[0] = size[1] = 0;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        void Push(int lista, T val)
        {
            if (list[lista].Length == size[lista])
            {
                var newAry = new T[size[lista] * 2];
                var newAgg = new T[size[lista] * 2];
                Array.Copy(list[lista], newAry, size[lista]);
                Array.Copy(agg[lista], newAgg, size[lista]);
                list[lista] = newAry;
                agg[lista] = newAgg;
            }
            if (size[lista] == 0) agg[lista][0] = val;
            else if (lista == 0) agg[lista][size[lista]] = fun(val, agg[lista][size[lista] - 1]);
            else agg[lista][size[lista]] = fun(agg[lista][size[lista] - 1], val);
            list[lista][size[lista]++] = val;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void PushBack(T val) => Push(1, val);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void PushFront(T val) => Push(0, val);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        T Pop(int lista)
        {
            var listb = 1 - lista;
            if (size[lista] == 0)
            {
                if (size[listb] == 0) throw new Exception();
                var mid = (size[listb] - 1) / 2;
                if (list[lista].Length <= mid)
                {
                    list[lista] = new T[mid + 1];
                    agg[lista] = new T[mid + 1];
                }
                size[lista] = 0;
                for (var i = mid; i >= 0; i--)
                {
                    if (size[lista] == 0) agg[lista][size[lista]] = list[listb][i];
                    else if (lista == 0) agg[lista][size[lista]] = fun(list[listb][i], agg[lista][size[lista] - 1]);
                    else agg[lista][size[lista]] = fun(agg[lista][size[lista] - 1], list[listb][i]);
                    list[lista][size[lista]++] = list[listb][i];
                }
                for (var i = mid + 1; i < size[listb]; i++)
                {
                    var idx = i - mid - 1;
                    if (idx == 0) agg[listb][idx] = list[listb][i];
                    else if (lista == 0) agg[listb][idx] = fun(list[listb][i], agg[listb][idx - 1]);
                    else agg[listb][idx] = fun(agg[listb][idx - 1], list[listb][i]);
                    list[listb][idx] = list[listb][i];
                }
                size[listb] -= size[lista];
            }
            return list[lista][--size[lista]];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public T PopBack() => Pop(1);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public T PopFront() => Pop(0);
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public T Aggregate()
        {
            if (size[0] == 0 && size[1] == 0) throw new Exception();
            else if (size[1] == 0) return agg[0][size[0] - 1];
            else if (size[0] == 0) return agg[1][size[1] - 1];
            else return fun(agg[0][size[0] - 1], agg[1][size[1] - 1]);
        }
    }
    // copy key class LIB_OfflinePathQuery
    partial class /* not copy key */ LIB_Tree
    {
        readonly struct Query
        {
            public readonly int idx;
            public readonly int l;
            public readonly int r;
            public Query(int idx, int l, int r) { this.idx = idx; this.l = l; this.r = r; }
        }
        readonly struct Edge
        {
            public readonly int idx;
            public readonly int a;
            public readonly int b;
            public Edge(int a, int b, Dictionary<long, int> table)
            {
                var key = 0L;
                if (a > b) key = ((long)a << 30) | (long)b;
                else key = ((long)b << 30) | (long)a;
                if (!table.ContainsKey(key))
                {
                    this.idx = table.Count;
                    table[key] = this.idx;
                }
                else
                {
                    this.idx = table[key];
                }
                this.a = a;
                this.b = b;
            }
        }
        public CPathQuery LIB_OfflinePathQuery(long root) => new CPathQuery((int)root, this);
        public class CPathQuery
        {
            LIB_Tree tree;
            Edge[] array;
            int[] vtxToArrayIndex;
            int root;
            List<Query> queries;
            int maxL;
            int maxR;
            int minL;
            int minR;
            int queryNum;
            (int nextL, int nextR)[] warpWayToL;
            (int nextL, int nextR)[] warpWayToR;
            Action<int, int> addRightEdge;
            Action<int, int> addLeftEdge;
            Action<int, int> deleteRightEdge;
            Action<int, int> deleteLeftEdge;
            Action<int> checker;
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CPathQuery(int root, LIB_Tree tree)
            {
                maxL = maxR = int.MinValue;
                minL = minR = int.MaxValue;
                queryNum = 0;
                queries = new List<Query>();
                addRightEdge = addLeftEdge = deleteRightEdge = deleteLeftEdge = (e1, e2) => { };
                checker = e => { };
                var table = new Dictionary<long, int>();
                this.root = root;
                this.tree = tree;
                array = new Edge[tree.N * 2 - 1];
                var tour = tree.EulerTour(root);
                vtxToArrayIndex = new int[tree.N];
                for (var i = 0; i < tour.Length - 1; ++i)
                {
                    if (tour[i].direction == 1)
                    {
                        array[i] = new Edge((int)tour[i].parent, (int)tour[i].node, table);
                        vtxToArrayIndex[tour[i].node] = i;
                    }
                    else
                    {
                        array[i] = new Edge((int)tour[i].node, (int)tour[i].parent, table);
                    }
                }
                warpWayToL = new (int nextL, int nextR)[tree.N * 2];
                warpWayToR = new (int nextL, int nextR)[tree.N * 2];
                var aikataA = new int[tree.N];
                for (var i = 1; i < array.Length; ++i)
                {
                    aikataA[array[i].idx] ^= i;
                    warpWayToL[i].nextR = array.Length;
                    warpWayToR[i].nextR = array.Length;
                }
                for (var i = 1; i < array.Length; ++i)
                {
                    var aikata = aikataA[array[i].idx] ^ i;
                    if (aikata < i)
                    {
                        warpWayToR[aikata - 1].nextR = i;
                        warpWayToR[i].nextL = aikata - 1;
                    }
                    else
                    {
                        warpWayToL[i].nextR = aikata + 1;
                        warpWayToL[aikata + 1].nextL = i;
                    }
                }
            }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public int AddQuery(long vtx1, long vtx2)
            {
                var l = vtxToArrayIndex[vtx1];
                var r = vtxToArrayIndex[vtx2];
                if (r < l) { var t = l; l = r; r = t; }
                if (maxL < l) maxL = l;
                if (minL > l) minL = l;
                if (maxR < r) maxR = r;
                if (minR > r) minR = r;
                queries.Add(new Query(queryNum, l + 1, r + 1));
                return queryNum++;
            }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            /// <summary>
            /// 指定した 辺 を追加するメソッドを設定
            /// (from, to)
            /// </summary>
            public CPathQuery SetAddEdgeMethod(Action<int, int> act)
            {
                addRightEdge = addLeftEdge = act;
                return this;
            }
            public CPathQuery SetAddRightEdgeMethod(Action<int, int> act)
            {
                addRightEdge = act;
                return this;
            }
            public CPathQuery SetAddLeftEdgeMethod(Action<int, int> act)
            {
                addLeftEdge = act;
                return this;
            }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            /// <summary>
            /// 指定した 辺 を削除するメソッドを設定
            /// (from, to)
            /// </summary>
            public CPathQuery SetDeleteEdgeMethod(Action<int, int> act)
            {
                deleteRightEdge = deleteLeftEdge = act;
                return this;
            }
            public CPathQuery SetDeleteRightEdgeMethod(Action<int, int> act)
            {
                deleteRightEdge = act;
                return this;
            }
            public CPathQuery SetDeleteLeftEdgeMethod(Action<int, int> act)
            {
                deleteLeftEdge = act;
                return this;
            }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            /// <summary>
            /// 指定した クエリindex の答えを処理するメソッドを設定
            /// </summary>
            public CPathQuery SetChecker(Action<int> act)
            {
                checker = act;
                return this;
            }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public void Execute()
            {
                Query[] sorted;
                if (maxL - minL > maxR - minR)
                {
                    var blockSize = Max(1, (int)(1.7320508 * (maxR - minR + 1) / Sqrt(2 * queryNum)));
                    sorted = queries.OrderBy(e => (e.r - minR + 1) / blockSize).ThenBy(e => (((e.r - minR + 1) / blockSize & 1) == 1) ? -e.l : e.l).ToArray();
                }
                else
                {
                    var blockSize = Max(1, (int)(1.7320508 * (maxL - minL + 1) / Sqrt(2 * queryNum)));
                    sorted = queries.OrderBy(e => (e.l - minL + 1) / blockSize).ThenBy(e => (((e.l - minL + 1) / blockSize & 1) == 1) ? -e.r : e.r).ToArray();
                }
                var lidx = 1;
                var ridx = 1;
                var isOdd = new bool[tree.N];
                ref var isOddRef = ref isOdd[0];
                ref var arrayRef = ref array[0];
                ref var warpWayToLRef = ref warpWayToL[0];
                ref var warpWayToRRef = ref warpWayToR[0];
                addRightEdge(-1, root);
                foreach (var item in sorted)
                {
                    while (true)
                    {
                        while (item.l <= Unsafe.Add(ref warpWayToLRef, lidx).nextL) lidx = Unsafe.Add(ref warpWayToLRef, lidx).nextL;
                        if (item.l >= lidx) break;
                        var edge = Unsafe.Add(ref arrayRef, --lidx);
                        if (Unsafe.Add(ref isOddRef, edge.idx)) deleteLeftEdge(edge.a, edge.b);
                        else addLeftEdge(edge.b, edge.a);
                        Unsafe.Add(ref isOddRef, edge.idx) = !Unsafe.Add(ref isOddRef, edge.idx);
                    }
                    while (true)
                    {
                        while (Unsafe.Add(ref warpWayToRRef, ridx - 1).nextR + 1 <= item.r) ridx = Unsafe.Add(ref warpWayToRRef, ridx - 1).nextR + 1;
                        if (ridx >= item.r) break;
                        var edge = Unsafe.Add(ref arrayRef, ridx++);
                        if (Unsafe.Add(ref isOddRef, edge.idx)) deleteRightEdge(edge.b, edge.a);
                        else addRightEdge(edge.a, edge.b);
                        Unsafe.Add(ref isOddRef, edge.idx) = !Unsafe.Add(ref isOddRef, edge.idx);
                    }
                    while (true)
                    {
                        while (Unsafe.Add(ref warpWayToLRef, lidx).nextR <= item.l) lidx = Unsafe.Add(ref warpWayToLRef, lidx).nextR;
                        if (lidx >= item.l) break;
                        var edge = Unsafe.Add(ref arrayRef, lidx++);
                        if (Unsafe.Add(ref isOddRef, edge.idx)) deleteLeftEdge(edge.b, edge.a);
                        else addLeftEdge(edge.a, edge.b);
                        Unsafe.Add(ref isOddRef, edge.idx) = !Unsafe.Add(ref isOddRef, edge.idx);
                    }
                    while (true)
                    {
                        while (item.r <= Unsafe.Add(ref warpWayToRRef, ridx - 1).nextL + 1) ridx = Unsafe.Add(ref warpWayToRRef, ridx - 1).nextL + 1;
                        if (item.r >= ridx) break;
                        var edge = Unsafe.Add(ref arrayRef, --ridx);
                        if (Unsafe.Add(ref isOddRef, edge.idx)) deleteRightEdge(edge.a, edge.b);
                        else addRightEdge(edge.b, edge.a);
                        Unsafe.Add(ref isOddRef, edge.idx) = !Unsafe.Add(ref isOddRef, edge.idx);
                    }
                    checker(item.idx);
                }
            }
        }
    }
    class LIB_Deque<T>
    {
        T[] array;
        int front, cap;
        public int Count;
        public T this[long i]
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get { return array[GetIndex((int)i)]; }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            set { array[GetIndex((int)i)] = value; }
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_Deque(long cap = 16)
        {
            array = new T[this.cap = (int)cap];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        int GetIndex(int i)
        {
            if (i >= cap) throw new Exception();
            var r = front + i;
            return r >= cap ? r - cap : r;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void PushFront(T x)
        {
            if (Count == cap) Extend();
            if (--front < 0) front += array.Length;
            array[front] = x;
            ++Count;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public T PopFront()
        {
            if (Count-- == 0) throw new Exception();
            var r = array[front++];
            if (front >= cap) front -= cap;
            return r;
        }
        public T Front => array[front];
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void PushBack(T x)
        {
            if (Count == cap) Extend();
            var i = front + Count++;
            array[i >= cap ? i - cap : i] = x;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public T PopBack()
        {
            if (Count == 0) throw new Exception();
            return array[GetIndex(--Count)];
        }
        public T Back => array[GetIndex(Count - 1)];
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        void Extend()
        {
            T[] nb = new T[cap << 1];
            if (front > cap - Count)
            {
                var l = array.Length - front; Array.Copy(array, front, nb, 0, l);
                Array.Copy(array, 0, nb, l, Count - l);
            }
            else Array.Copy(array, front, nb, 0, Count);
            array = nb; front = 0; cap <<= 1;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void Insert(long i, T x)
        {
            if (i > Count) throw new Exception();
            this.PushFront(x);
            for (int j = 0; j < i; j++) this[j] = this[j + 1];
            this[i] = x;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public T RemoveAt(long i)
        {
            if (i < 0 || i >= Count) throw new Exception();
            var r = this[i];
            for (var j = i; j > 0; j--) this[j] = this[j - 1];
            this.PopFront();
            return r;
        }
    }
    // copy key class LIB_ReRooting
    partial class /* not copy key */ LIB_Tree
    {
        /// <summary>
        /// 全方位木DP
        /// </summary>
        /// <returns>2次元配列[node, parent]の部分木のDP値。parent=-1はnodeをルートとした木の値</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public CReRooting<T> LIB_ReRooting<T>() => new CReRooting<T>(this);
        public class CReRooting<T>
        {
            LIB_Tree tree;
            Dictionary<int, T>[] dp;
            Func<T, T, T> f;
            Func<long, T> g;
            Func<long, long, T, T> g2;
            Func<T, T, T> h;
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CReRooting(LIB_Tree tree)
            {
                this.tree = tree;
                dp = Enumerable.Repeat(0, tree.N).Select(_ => new Dictionary<int, T>()).ToArray();
                f = (x, y) => throw new NotImplementedException();
                g = v => throw new NotImplementedException();
                g2 = (r, p, v) => v;
                h = (v, t) => t;
            }
            public T this[long vtx, long parent]
            {
                [MethodImpl(MethodImplOptions.AggressiveInlining)]
                get { return dp[vtx][(int)parent]; }
            }
            /// <summary>
            /// 部分木と部分木のマージ(subtree, subtree)するメソッドを設定
            /// </summary>
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CReRooting<T> MergeSubtrees(Func<T, T, T> mergeSubTrees) { f = mergeSubTrees; return this; }
            /// <summary>
            /// 頂点番号から値を取得するメソッドを設定
            /// </summary>
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CReRooting<T> VertexToValue(Func<long, T> idxToVal) { g = idxToVal; return this; }
            /// <summary>
            /// 頂点番号(root, parent)で表す辺とrootをルートとする部分木をマージするメソッドを設定
            /// </summary>
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CReRooting<T> MergeEdgeAndSubtree(Func<long, long, T, T> mergeEdgeAndSubtree) { g2 = mergeEdgeAndSubtree; return this; }
            /// <summary>
            /// 頂点と部分木の結果をマージ(vertex, subtrees)するメソッドを設定
            /// </summary>
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CReRooting<T> MergeVertexAndSubtree(Func<T, T, T> mergeVertexAndSubtree) { h = mergeVertexAndSubtree; return this; }
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public CReRooting<T> Build()
            {
                var done = new bool[tree.N];
                Action<long, long, T> upd = (vtx, rt, val) =>
                {
                    if (vtx == -1) return;
                    if (done[vtx]) dp[vtx][-1] = f(dp[vtx][-1], g2(rt, vtx, val));
                    else dp[vtx][-1] = g2(rt, vtx, val);
                    done[vtx] = true;
                };
                foreach (var item in tree.BFSFromLeaf(0))
                {
                    var ary = tree.path[item.node].Where(e => e != item.parent).ToArray();
                    var val = g(item.node);
                    if (ary.Length > 0)
                    {
                        var acc = g2(ary[0], item.node, dp[ary[0]][(int)item.node]);
                        foreach (var item2 in ary.Skip(1)) acc = f(acc, g2(item2, item.node, dp[item2][(int)item.node]));
                        val = h(val, acc);
                    }
                    upd(item.parent, item.node, dp[item.node][(int)item.parent] = val);
                }
                var swag = new LIB_SlidingWindowAggregation<T>(f);
                Action<int, int> process = (node, parent) =>
                {
                    var val = g(node);
                    if (tree.path[node].Count == 1)
                    {
                        var x = tree.path[node][0];
                        if (x != parent) upd(x, node, dp[node][x] = val);
                    }
                    else if (tree.path[node].Count == 2)
                    {
                        var x = tree.path[node][0]; var y = tree.path[node][1];
                        if (x != parent) upd(x, node, dp[node][x] = h(val, g2(y, node, dp[y][node])));
                        if (y != parent) upd(y, node, dp[node][y] = h(val, g2(x, node, dp[x][node])));
                    }
                    else if (tree.path[node].Count == 3)
                    {
                        var x = tree.path[node][0]; var y = tree.path[node][1]; var z = tree.path[node][2];
                        if (x != parent) upd(x, node, dp[node][x] = h(val, f(g2(y, node, dp[y][node]), g2(z, node, dp[z][node]))));
                        if (y != parent) upd(y, node, dp[node][y] = h(val, f(g2(x, node, dp[x][node]), g2(z, node, dp[z][node]))));
                        if (z != parent) upd(z, node, dp[node][z] = h(val, f(g2(x, node, dp[x][node]), g2(y, node, dp[y][node]))));
                    }
                    else if (tree.path[node].Count == 4)
                    {
                        var x = tree.path[node][0]; var y = tree.path[node][1]; var z = tree.path[node][2]; var w = tree.path[node][3];
                        var xy = f(g2(x, node, dp[x][node]), g2(y, node, dp[y][node]));
                        var zw = f(g2(z, node, dp[z][node]), g2(w, node, dp[w][node]));
                        if (x != parent) upd(x, node, dp[node][x] = h(val, f(g2(y, node, dp[y][node]), zw)));
                        if (y != parent) upd(y, node, dp[node][y] = h(val, f(g2(x, node, dp[x][node]), zw)));
                        if (z != parent) upd(z, node, dp[node][z] = h(val, f(xy, g2(w, node, dp[w][node]))));
                        if (w != parent) upd(w, node, dp[node][w] = h(val, f(xy, g2(z, node, dp[z][node]))));
                    }
                    else
                    {
                        swag.Clear();
                        var pre = new T[tree.path[node].Count];
                        for (var i = 0; i < pre.Length; ++i) swag.PushBack(pre[i] = g2(tree.path[node][i], node, dp[tree.path[node][i]][node]));
                        for (var i = 0; i < pre.Length; ++i)
                        {
                            var item2 = tree.path[node][i];
                            swag.PopFront();
                            if (item2 != parent) upd(item2, node, dp[node][item2] = h(val, swag.Aggregate()));
                            swag.PushBack(pre[i]);
                        }
                    }
                };
                foreach (var item in tree.BFSFromRoot(0)) process((int)item.node, (int)item.parent);
                for (var i = 1; i < tree.N; i++) dp[i][-1] = done[i] ? h(g(i), dp[i][-1]) : g(i);
                return this;
            }
        }
    }
    class LIB_FastIO
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_FastIO() { str = Console.OpenStandardInput(); }
        readonly Stream str;
        readonly byte[] buf = new byte[2048];
        int len, ptr;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        byte read()
        {
            if (ptr >= len)
            {
                ptr = 0;
                if ((len = str.Read(buf, 0, 2048)) <= 0)
                {
                    return 0;
                }
            }
            return buf[ptr++];
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        char Char()
        {
            byte b = 0;
            do b = read();
            while (b < 33 || 126 < b);
            return (char)b;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        virtual public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        virtual public long Long()
        {
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != '-' && (b < '0' || '9' < b));
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = (ret << 3) + (ret << 1) + b - '0';
            }
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        virtual public double Double() { return double.Parse(Scan(), CultureInfo.InvariantCulture); }
    }
    class LIB_FastIODebug : LIB_FastIO
    {
        Queue<string> param = new Queue<string>();
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        string NextString() { if (param.Count == 0) foreach (var item in Console.ReadLine().Split(' ')) param.Enqueue(item); return param.Dequeue(); }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_FastIODebug() { }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public override string Scan() => NextString();
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public override long Long() => long.Parse(NextString());
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public override double Double() => double.Parse(NextString());
    }
    partial class LIB_Tree
    {
        int N;
        List<int>[] path;
        Dictionary<int, int>[] pathWithCount;
        List<(int u, int v)> edges;
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public LIB_Tree(long n)
        {
            N = (int)n;
            path = Enumerable.Repeat(0, N).Select(_ => new List<int>()).ToArray();
            pathWithCount = Enumerable.Repeat(0, N).Select(_ => new Dictionary<int, int>()).ToArray();
            edges = new List<(int u, int v)>();
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public void AddPath(long u, long v)
        {
            if (u >= N || v >= N) throw new Exception();
            path[u].Add((int)v);
            path[v].Add((int)u);
            pathWithCount[u].Add((int)v, edges.Count);
            pathWithCount[v].Add((int)u, edges.Count);
            edges.Add(((int)u, (int)v));
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public int[] GetSurround(long u) => path[u].ToArray();
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public List<(long node, long parent)> BFSFromRoot(long root)
        {
            var bfsList = new List<(long node, long parent)>();
            var q = new Queue<int>();
            var done = new bool[N];
            bfsList.Add((root, -1));
            done[root] = true;
            q.Enqueue((int)root);
            while (q.Count > 0)
            {
                var w = q.Dequeue();
                foreach (var edge in pathWithCount[w])
                {
                    var i = edge.Key;
                    if (done[i]) continue;
                    done[i] = true;
                    q.Enqueue(i);
                    bfsList.Add((i, w));
                }
            }
            return bfsList;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public long[] GetDistanceFrom(long root)
        {
            var ret = new long[N];
            foreach (var item in BFSFromRoot(root))
            {
                if (item.parent == -1) continue;
                ret[item.node] = ret[item.parent] + 1;
            }
            return ret;
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public int[] GetJuusin()
        {
            var center = new List<int>();
            var dp = new long[N];
            foreach (var item in BFSFromLeaf(0))
            {
                dp[item.node] += 1;
                var ok = false;
                foreach (var edge in path[item.node])
                {
                    var idx = edge;
                    if (idx == item.parent) continue;
                    dp[item.node] += dp[idx];
                    if (dp[idx] <= N / 2) ok = true;
                }
                if (ok)
                {
                    if (N - dp[item.node] <= N / 2)
                    {
                        center.Add((int)item.node);
                    }
                }
            }
            return center.ToArray();
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public int[] GetTyokkei()
        {
            var dist1 = GetDistanceFrom(0);
            var maxPos = 0;
            var maxDist = 0L;
            for (var i = 0; i < N; i++)
            {
                if (maxDist < dist1[i])
                {
                    maxDist = dist1[i];
                    maxPos = i;
                }
            }
            var dist2 = new int[N];
            var parent = new int[N];
            maxDist = 0;
            var anotherMaxPos = 0L;
            foreach (var item in BFSFromRoot(maxPos))
            {
                parent[item.node] = (int)item.parent;
                if (item.parent == -1) continue;
                dist2[item.node] = dist2[item.parent] + 1;
                if (maxDist < dist2[item.node])
                {
                    maxDist = dist2[item.node];
                    anotherMaxPos = item.node;
                }
            }
            var nownode = (int)anotherMaxPos;
            var ret = new List<int>();
            while (nownode != -1)
            {
                ret.Add(nownode);
                nownode = parent[nownode];
            }
            return ret.ToArray();
        }
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public List<(long node, long parent)> BFSFromLeaf(long root) => BFSFromRoot(root).ToArray().Reverse().ToList();
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public (long node, long parent, long direction)[] EulerTour(long root)
        {
            var eulerList = new (long node, long parent, long direction)[N << 1];
            ref var eulerListRef = ref eulerList[0];
            var stack = new int[N << 1];
            ref var stackref = ref stack[0];
            var si = 0;
            Unsafe.Add(ref stackref, si++) = (int)root + 1;
            var idx = 0;
            var par = new int[N];
            ref var parref = ref par[0];
            Unsafe.Add(ref parref, (int)root) = -1;
            while (si > 0)
            {
                var vtx = Unsafe.Add(ref stackref, --si);
                if (vtx < 0)
                {
                    vtx *= -1;
                    --vtx;
                    Unsafe.Add(ref eulerListRef, idx) = (vtx, Unsafe.Add(ref parref, vtx), -1);
                }
                else
                {
                    Unsafe.Add(ref stackref, si++) = -vtx;
                    --vtx;
                    var pare = Unsafe.Add(ref parref, vtx);
                    Unsafe.Add(ref eulerListRef, idx) = (vtx, pare, 1);
                    foreach (var edge in path[vtx])
                    {
                        var item = edge;
                        if (item == pare) continue;
                        Unsafe.Add(ref parref, item) = vtx;
                        Unsafe.Add(ref stackref, si++) = item + 1;
                    }
                }
                ++idx;
            }
            return eulerList;
        }
    }
}
0