結果

問題 No.3071 Double Speedrun
コンテスト
ユーザー tobisatis
提出日時 2025-03-21 23:22:49
言語 C#
(.NET 8.0.404)
結果
TLE  
実行時間 -
コード長 6,578 bytes
コンパイル時間 8,767 ms
コンパイル使用メモリ 171,652 KB
実行使用メモリ 173,312 KB
最終ジャッジ日時 2025-03-21 23:23:07
合計ジャッジ時間 17,095 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge7
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 1 TLE * 1 -- * 12
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
  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 (112 ミリ秒)。
  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 # 

#nullable enable

using System.Numerics;

void Run()
{
    var h = Int();
    var w = Int();
    var g = new bool[h, w];
    for (var i = 0; i < h; i++)
    {
        var row = String();
        for (var j = 0; j < w; j++) g[i, j] = row[j] == '.';
    }
    var rs = new int[h, w];
    for (var i = 0; i < h; i++)
    {
        var ls = w;
        for (var j = w - 1; j >= 0; j--)
        {
            if (!g[i, j]) ls = j;
            rs[i, j] = ls;
        }
    }
    var dp = w.Repeat(() => new RangeAddPointGet<ModInt>(w));
    dp[1].Add(0, 1, 1);
    var f = true;
    var x = 0;
    for (var lp = 0; lp < h * 2 - 4; lp++)
    {
        var ep = w.Repeat(() => new RangeAddPointGet<ModInt>(w));
        for (var i = 0; i < w; i++) for (var j = 0; j < w; j++)
        {
            if (!g[x, i]) continue;
            var v = dp[i].Get(j);
            if (v == 0) continue;
            if (f)
            {
                if (i <= j) continue;
                var start = Math.Max(i, j + 1);
                if (start >= w) continue;
                var k = rs[x, start];
                ep[j].Add(start, k, v);
            }
            else
            {
                if (i >= j) continue;
                var k = Math.Min(rs[x, i], j);
                ep[j].Add(i, k, v);
            }
        }
        dp = ep;
        if (f) x++;
        f = !f;
    }
    ModInt ans = 0;
    for (var i = 0; i < w; i++) for (var j = 0; j < w; j++) if(g[h - 2, i] && g[h - 1, j]) ans += dp[i].Get(j);
    Out(ans);
}

#region
AtCoderIO _io_;
var _backend_ = new StandardIOBackend();
_io_ = new(){ Backend = _backend_ };
Run();
_backend_.Flush();

string String() => _io_.Next();
int Int() => int.Parse(String());
void Out(object? x, string? sep = null) => _io_.Out(x, sep);

class AtCoderIO
{
    public required StandardIOBackend Backend { get; init; }

    Memory<string> _input = Array.Empty<string>();
    int _iter = 0;
    public string Next()
    {
        while (_iter >= _input.Length) (_input, _iter) = (Backend.ReadLine().Split(' '), 0);
        return _input.Span[_iter++];
    }

    public void Out(object? x, string? separator = null)
    {
        if (x == null) return;
        separator ??= Environment.NewLine;
        if (x is System.Collections.IEnumerable a and not string)
        {
            var objects = a.Cast<object>();
            if (separator == Environment.NewLine && !objects.Any()) return;
            x = string.Join(separator, objects);
        }
        Backend.WriteLine(x);
    }
}

class StandardIOBackend
{
    readonly StreamReader _sr = new(Console.OpenStandardInput());
    readonly StreamWriter _sw = new(Console.OpenStandardOutput()) { AutoFlush = false };
    public string ReadLine() => _sr.ReadLine()!;
    public void WriteLine(object? value) => _sw.WriteLine(value);
    public void Flush() => _sw.Flush();
}
#endregion

static class Extensions
{
    public static T[] Repeat<T>(this int time, Func<T> F) => Enumerable.Range(0, time).Select(_ => F()).ToArray();
}

interface IAdditiveGroup<T> :
    IAdditiveIdentity<T, T>,
    IAdditionOperators<T, T, T>,
    ISubtractionOperators<T, T, T>
    where T : IAdditiveGroup<T>
{
    T AdditiveInverse();
}

interface IMultiplicativeGroup<T> :
    IMultiplicativeIdentity<T, T>,
    IMultiplyOperators<T, T, T>,
    IDivisionOperators<T, T, T>
    where T : IMultiplicativeGroup<T>
{
    T MultiplicativeInverse();
}

readonly record struct ModInt :
    IEqualityOperators<ModInt, ModInt, bool>,
    IAdditiveGroup<ModInt>,
    IMultiplicativeGroup<ModInt>
{
    public const int Mod = 998244353;
    int V { get; init; }
    public ModInt(long value)
    {
        var v = value % Mod;
        if (v < 0) v += Mod;
        V = (int)v;
    }
    static ModInt New(int value) => new(){ V = value };

    public static implicit operator ModInt(long v) => new(v);
    public static implicit operator int(ModInt modInt) => modInt.V;

    public static ModInt AdditiveIdentity => New(0);
    public static ModInt operator +(ModInt a, ModInt b)
    {
        var v = a.V + b.V;
        if (v >= Mod) v -= Mod;
        return New(v);
    }
    public ModInt AdditiveInverse()
    {
        if (V == 0) return AdditiveIdentity;
        return New(Mod - V);
    }
    public static ModInt operator -(ModInt a, ModInt b)
    {
        var v = a.V - b.V;
        if (v < 0) v += Mod;
        return New(v);
    }

    public static ModInt MultiplicativeIdentity => New(1);
    public static ModInt operator *(ModInt a, ModInt b) => New((int)((long)a.V * b.V % Mod));
    public ModInt MultiplicativeInverse()
    {
        if (V == 0) throw new DivideByZeroException();
        var (d, x, _) = ExtendedGCD(V, Mod);
        if (d > 1) throw new DivideByZeroException();
        return x;
    }
    public static ModInt operator /(ModInt a, ModInt b) => a * b.MultiplicativeInverse();

    static long Power(long v, ulong p, long mod)
    {
        var (res, k) = (1L, v);
        while (p > 0)
        {
            if ((p & 1) > 0) res = res * k % mod;
            k = k * k % mod;
            p >>= 1;
        }
        return res;
    }
    public ModInt Power(long p) => p < 0 ? (MultiplicativeIdentity / V).Power(-p) : Power(V, (ulong)p, Mod);

    static (long d, long x, long y) ExtendedGCD(long a, long b)
    {
        var (x0, y0, x1, y1) = (1L, 0L, 0L, 1L);
        while (b != 0)
        {
            var q = a / b;
            (a, b) = (b, a - q * b);
            (x0, y0, x1, y1) = (x1, y1, x0 - q * x1, y0 - q * y1);
        }
        return (a, x0, y0);
    }

    public override string ToString() => V.ToString();
}

class FenwickTree<T> where T : IAdditiveGroup<T>
{
    public FenwickTree(int length) { _values = new T[length + 2]; }
    public void Add(int i, T value)
    {
        var values = _values.Span;
        while (i < values.Length)
        {
            values[i] += value;
            i += i & -i;
        }
    }
    public T Sum(int i)
    {
        var values = _values.Span;
        var res = T.AdditiveIdentity;
        while (i > 0)
        {
            res += values[i];
            i -= i & -i;
        }
        return res;
    }
    readonly Memory<T> _values;
}

// [0..N)
class RangeAddPointGet<T> where T : IAdditiveGroup<T>
{
    public RangeAddPointGet(int length) { _data = new FenwickTree<T>(length); }
    public void Add(int l, int r, T value) // [l, r)
    {
        _data.Add(l + 1, value);
        _data.Add(r + 1, T.AdditiveIdentity - value);
    }
    public T Get(int at) => _data.Sum(at + 1);
    readonly FenwickTree<T> _data;
}
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