#493371 (C#(csc)) No.1075 木の上の山

提出ソース

結果

問題	No.1075 木の上の山
ユーザー	EmKjp
提出日時	2020-06-06 12:44:26
言語	C#(csc) (csc 3.9.0)
結果	AC
実行時間	294 ms / 2,000 ms
コード長	11,593 bytes
コンパイル時間	4,676 ms
コンパイル使用メモリ	114,592 KB
実行使用メモリ	73,568 KB
最終ジャッジ日時	2023-08-25 00:30:32
合計ジャッジ時間	11,395 ms
ジャッジサーバーID （参考情報）	judge12 / judge13

このコードへのチャレンジ
（要ログイン）

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	62 ms 23,756 KB
testcase_01	AC	63 ms 19,692 KB
testcase_02	AC	63 ms 23,788 KB
testcase_03	AC	62 ms 21,712 KB
testcase_04	AC	63 ms 21,684 KB
testcase_05	AC	63 ms 21,716 KB
testcase_06	AC	62 ms 21,824 KB
testcase_07	AC	65 ms 21,632 KB
testcase_08	AC	65 ms 21,688 KB
testcase_09	AC	65 ms 21,692 KB
testcase_10	AC	66 ms 21,752 KB
testcase_11	AC	66 ms 23,724 KB
testcase_12	AC	67 ms 21,740 KB
testcase_13	AC	67 ms 21,852 KB
testcase_14	AC	68 ms 23,744 KB
testcase_15	AC	69 ms 23,796 KB
testcase_16	AC	67 ms 21,720 KB
testcase_17	AC	293 ms 73,568 KB
testcase_18	AC	291 ms 64,476 KB
testcase_19	AC	289 ms 65,152 KB
testcase_20	AC	288 ms 64,624 KB
testcase_21	AC	273 ms 52,188 KB
testcase_22	AC	279 ms 52,024 KB
testcase_23	AC	275 ms 53,236 KB
testcase_24	AC	281 ms 51,108 KB
testcase_25	AC	280 ms 50,112 KB
testcase_26	AC	294 ms 59,892 KB
testcase_27	AC	282 ms 59,088 KB
testcase_28	AC	281 ms 55,028 KB
testcase_29	AC	284 ms 59,216 KB
testcase_30	AC	287 ms 63,912 KB
testcase_31	AC	281 ms 61,208 KB

権限があれば一括ダウンロードができます

コンパイルメッセージ

Microsoft (R) Visual C# Compiler version 3.9.0-6.21124.20 (db94f4cc)
Copyright (C) Microsoft Corporation. All rights reserved.

ソースコード

raw source code

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Text;
using System.Linq;

using E = System.Linq.Enumerable;

internal partial class Solver {
    public void Run() {
        var n = ni();
        var k = ni();
        var adj = Enumerable.Range(0, n).Select(_ => new List<int>()).ToArray();
        var mod = ModInt.SetModValue(1000000000 + 7);
        for (int i = 0; i < n - 1; i++) {
            var a = ni() - 1;
            var b = ni() - 1;
            adj[a].Add(b);
            adj[b].Add(a);
        }
        ModInt[][] dp = new ModInt[n][];
        var init = E.Repeat<ModInt>(1, k + 1).ToArray();
        init[0] = 0;

        ModInt[] dfs(int pos, int parent = -1) {
            var val = init.ToArray();
            foreach (var child in adj[pos]) {
                if (child == parent) continue;
                var sub = dfs(child, pos);
                for (int i = 1; i <= k; i++) {
                    val[i] *= sub[i];
                }
            }
            for (int i = 1; i <= k; i++) {
                val[i] += val[i - 1];
            }
            dp[pos] = val;
            return val;
        }

        dfs(0);

        ModInt[] merge(ModInt[] a, ModInt[] b) {
            var m = new ModInt[k + 1];
            for (int i = 1; i <= k; i++) {
                m[i] = a[i] * b[i];
            }
            return m;
        }

        ModInt ans = 0;

        void dfs2(int pos, int parent, ModInt[] fromParent) {
            var count = adj[pos].Count;
            var subResults = new ModInt[count][];
            int index = 0;
            foreach (var child in adj[pos]) {
                if (child == parent) {
                    subResults[index++] = fromParent;
                } else {
                    subResults[index++] = dp[child];
                }
            }
            if (count > 0) {
                var left = new ModInt[count][];
                var right = new ModInt[count][];
                left[0] = subResults[0];
                right[count - 1] = subResults[count - 1];
                for (int i = 1; i < count; i++) {
                    left[i] = merge(left[i - 1], subResults[i]);
                }
                for (int i = count - 2; i >= 0; i--) {
                    right[i] = merge(right[i + 1], subResults[i]);
                }
                for (int i = 0; i < count; i++) {
                    var child = adj[pos][i];
                    if (child == parent) {
                        var sub = merge(i - 1 >= 0 ? left[i - 1] : init, i + 1 < count ? right[i + 1] : init);
                        var shift = subResults[i].ToArray();
                        for (int j = k; j > 0; j--) {
                            shift[j] = shift[j - 1];
                        }
                        shift[0] = 0;
                        sub = merge(sub, shift);
                        for (int j = 1; j <= k; j++) sub[j] += sub[j - 1];
                        ans += sub[k];
                    } else {
                        var sub = merge(i - 1 >= 0 ? left[i - 1] : init, i + 1 < count ? right[i + 1] : init);
                        for (int j = 1; j <= k; j++) sub[j] += sub[j - 1];
                        dfs2(child, pos, sub);
                    }
                }
                if (parent == -1) {
                    var sub = left[count - 1];
                    for (int j = 1; j <= k; j++) sub[j] += sub[j - 1];
                    ans += sub[k];
                }
            } else {
                ans += k;
            }
        }

        dfs2(0, -1, null);

        cout.WriteLine(ans);
    }
}


public struct ModInt : IEquatable<ModInt> {
    private static int mod = 0;
    private long _value;

    public ModInt(long x) {
        _value = x;
        Normalize();
    }

    private static long RegularMod(long x, int mod) {
        if (x >= mod) {
            if (x < 2 * mod) {
                return x - mod;
            }

            return x % mod;
        }
        if (x >= 0) {
            return x;
        }

        x = mod - RegularMod(-x, mod);
        if (x == mod) {
            return 0;
        }

        return x;
    }

    public static int SetModValue(int m) {
        return mod = m;
    }

    private void Normalize() {
        _value = RegularMod(_value, mod);
    }

    public override string ToString() {
        return _value.ToString(CultureInfo.InvariantCulture);
    }

    public int ToInt() {
        return (int)_value;
    }

    public static bool operator ==(ModInt c1, ModInt c2) {
        return c1._value == c2._value;
    }

    public static bool operator !=(ModInt c1, ModInt c2) {
        return !(c1 == c2);
    }

    public static ModInt operator +(ModInt x, ModInt y) {
        return new ModInt(x._value + y._value);
    }
    public static ModInt operator -(ModInt x, ModInt y) {
        return new ModInt(x._value - y._value);
    }
    public static ModInt operator -(ModInt x) {
        return new ModInt(-x._value);
    }
    public static ModInt operator *(ModInt x, ModInt y) {
        return new ModInt(x._value * y._value);
    }
    public static ModInt operator /(ModInt x, ModInt y) {
        return new ModInt(x._value * Inverse(y._value, mod));
    }
    public static ModInt operator ++(ModInt x) {
        return x + 1;
    }
    public static ModInt operator --(ModInt x) {
        return x - 1;
    }
    public static ModInt Pow(ModInt x, long n) {
        ModInt r = 1;
        while (n > 0) {
            if ((n & 1) != 0) {
                r *= x;
            }

            x *= x;
            n >>= 1;
        }
        return r;
    }
    private static long ExtendedGcd(long a, long b, ref long x, ref long y) {
        if (b == 0) {
            x = 1; y = 0;
            return a;
        } else {
            var d = ExtendedGcd(b, a % b, ref y, ref x);
            y -= a / b * x;
            return d;
        }
    }

    private static long Inverse(long a, long mod) {
        long x = 0, y = 0;
        if (ExtendedGcd(a, mod, ref x, ref y) == 1) {
            return (x + mod) % mod;
        } else {
            throw new Exception("Invalid inverse " + a + " " + mod);
        }
    }

    public static implicit operator ModInt(long x) {
        return new ModInt(x);
    }

    public override bool Equals(object obj) {
        if (obj == null) {
            return false;
        }
        return _value.Equals(((ModInt)obj)._value);
    }

    public override int GetHashCode() {
        return _value.GetHashCode();
    }

    public bool Equals(ModInt other) {
        return _value.Equals(other._value);
    }
}

// PREWRITEN CODE BEGINS FROM HERE

static public class StringExtensions {
    static public string JoinToString<T>(this IEnumerable<T> source, string separator = " ") {
        return string.Join(separator, source);
    }
}

internal partial class Solver : Scanner {
    public static void Main() {
#if LOCAL
        byte[] inputBuffer = new byte[1000000];
        var inputStream = Console.OpenStandardInput(inputBuffer.Length);
        using (var reader = new StreamReader(inputStream, Console.InputEncoding, false, inputBuffer.Length)) {
            Console.SetIn(reader);
            new Solver(Console.In, Console.Out).Run();
        }
#else
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver(Console.In, Console.Out).Run();
        Console.Out.Flush();
#endif
    }

#pragma warning disable IDE0052
    private readonly TextReader cin;
    private readonly TextWriter cout;
    private readonly TextWriter cerr;
#pragma warning restore IDE0052

    public Solver(TextReader reader, TextWriter writer)
        : base(reader) {
        cin = reader;
        cout = writer;
        cerr = Console.Error;
    }

    public Solver(string input, TextWriter writer)
        : this(new StringReader(input), writer) {
    }

#pragma warning disable IDE1006
#pragma warning disable IDE0051
    private int ni() { return NextInt(); }
    private int[] ni(int n) { return NextIntArray(n); }
    private long nl() { return NextLong(); }
    private long[] nl(int n) { return NextLongArray(n); }
    private double nd() { return NextDouble(); }
    private double[] nd(int n) { return NextDoubleArray(n); }
    private string ns() { return Next(); }
    private string[] ns(int n) { return NextArray(n); }
#pragma warning restore IDE1006
#pragma warning restore IDE0051
}

internal static class LinqPadExtension {
    [Conditional("DEBUG")]
    public static void Dump<T>(this T obj) {
#if DEBUG
        LINQPad.Extensions.Dump(obj);
#endif
    }
}

public class Scanner {
    private readonly TextReader Reader;
    private readonly CultureInfo ci = CultureInfo.InvariantCulture;

    private readonly char[] buffer = new char[2 * 1024];
    private int cursor = 0, length = 0;
    private string Token;
    private readonly StringBuilder sb = new StringBuilder(1024);

    public Scanner()
        : this(Console.In) {
    }

    public Scanner(TextReader reader) {
        Reader = reader;
    }

    public int NextInt() { return checked((int)NextLong()); }
    public long NextLong() {
        var s = Next();
        long r = 0;
        int i = 0;
        bool negative = false;
        if (s[i] == '-') {
            negative = true;
            i++;
        }
        for (; i < s.Length; i++) {
            r = r * 10 + (s[i] - '0');
#if DEBUG
            if (!char.IsDigit(s[i])) throw new FormatException();
#endif
        }
        return negative ? -r : r;
    }
    public double NextDouble() { return double.Parse(Next(), ci); }
    public string[] NextArray(int size) {
        string[] array = new string[size];
        for (int i = 0; i < size; i++) {
            array[i] = Next();
        }

        return array;
    }
    public int[] NextIntArray(int size) {
        int[] array = new int[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextInt();
        }

        return array;
    }

    public long[] NextLongArray(int size) {
        long[] array = new long[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextLong();
        }

        return array;
    }

    public double[] NextDoubleArray(int size) {
        double[] array = new double[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextDouble();
        }

        return array;
    }

    public string Next() {
        if (Token == null) {
            if (!StockToken()) {
                throw new Exception();
            }
        }
        var token = Token;
        Token = null;
        return token;
    }

    public bool HasNext() {
        if (Token != null) {
            return true;
        }

        return StockToken();
    }

    private bool StockToken() {
        while (true) {
            sb.Clear();
            while (true) {
                if (cursor >= length) {
                    cursor = 0;
                    if ((length = Reader.Read(buffer, 0, buffer.Length)) <= 0) {
                        break;
                    }
                }
                var c = buffer[cursor++];
                if (33 <= c && c <= 126) {
                    sb.Append(c);
                } else {
                    if (sb.Length > 0) break;
                }
            }

            if (sb.Length > 0) {
                Token = sb.ToString();
                return true;
            }

            return false;
        }
    }
}

yukicoder

結果

テストケース

コンパイルメッセージ

ソースコード