結果

問題 No.3538 Not First Place
コンテスト
ユーザー nauclhlt
提出日時 2026-02-28 15:02:58
言語 C++17
(gcc 15.2.0 + boost 1.89.0)
コンパイル:
g++-15 -O2 -lm -std=c++17 -Wuninitialized -DONLINE_JUDGE -o a.out _filename_
実行:
./a.out
結果
AC  
実行時間 1,039 ms / 5,000 ms
コード長 6,374 bytes
記録
記録タグの例:
初AC ショートコード 純ショートコード 純主流ショートコード 最速実行時間
コンパイル時間 1,438 ms
コンパイル使用メモリ 216,008 KB
実行使用メモリ 214,400 KB
最終ジャッジ日時 2026-05-08 20:50:21
合計ジャッジ時間 6,929 ms
ジャッジサーバーID
（参考情報） 		judge1_1 / judge3_1
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 * 2
other AC * 26
権限があれば一括ダウンロードができます

ソースコード

diff #
raw source code 

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define CONST_MOD 998244353L
// #define CONST_MOD 1000000007L
struct ModInt
{
    long long Value;

public:
    ModInt()
    {
        Value = 0L;
    }

    ModInt(long long value)
    {
        Value = value;
    }

    ModInt Power(long long exp) const
    {
        if (exp <= -1L)
        {
            return ModInt(1L) / Power(-exp);
        }
        if (exp == 0L)
            return 1L;
        if (exp == 1L)
            return *this;

        ModInt m = Power(exp / 2L);
        m = m * m;
        if (exp % 2L == 1L)
        {
            m = m * (*this);
        }

        return m;
    }

    ModInt Inv() const
    {
        return this->Power(CONST_MOD - 2L);
    }

    ModInt operator+() const
    {
        return *this;
    }

    ModInt operator-() const
    {
        return ModInt(-Value);
    }

    friend ModInt operator+(const ModInt& left, const ModInt& right)
    {
        return ModInt(SafeMod(left.Value + right.Value));
    }

    friend ModInt operator+(const ModInt& left, const long long& right)
    {
        return ModInt(SafeMod(left.Value + right));
    }

    friend ModInt operator+(const long long& left, const ModInt& right)
    {
        return ModInt(SafeMod(left + right.Value));
    }

    ModInt& operator+=(const ModInt& x)
    {
        Value += x.Value;
        Value = SafeMod(Value);

        return *this;
    }

    ModInt& operator+=(const long long& x)
    {
        Value += x;
        Value = SafeMod(Value);

        return *this;
    }

    friend ModInt operator-(const ModInt& left, const ModInt& right)
    {
        return ModInt(SafeMod(left.Value - right.Value));
    }

    friend ModInt operator-(const ModInt& left, const long long& right)
    {
        return ModInt(SafeMod(left.Value - right));
    }

    friend ModInt operator-(const long long& left, const ModInt& right)
    {
        return ModInt(SafeMod(left - right.Value));
    }

    ModInt& operator-=(const ModInt& x)
    {
        Value -= x.Value;
        Value = SafeMod(Value);

        return *this;
    }

    ModInt& operator-=(const long long& x)
    {
        Value -= x;
        Value = SafeMod(Value);

        return *this;
    }

    friend ModInt operator*(const ModInt& left, const ModInt& right)
    {
        return ModInt(SafeMod(left.Value * right.Value));
    }

    friend ModInt operator*(const ModInt& left, const long long& right)
    {
        return ModInt(SafeMod(left.Value * right));
    }

    friend ModInt operator*(const long long& left, const ModInt& right)
    {
        return ModInt(SafeMod(left * right.Value));
    }

    ModInt& operator*=(const ModInt& x)
    {
        Value *= x.Value;
        Value = SafeMod(Value);

        return *this;
    }

    ModInt& operator*=(const long long& x)
    {
        Value *= x;
        Value = SafeMod(Value);

        return *this;
    }

    friend ModInt operator /(const ModInt& left, const ModInt& right)
    {
        ModInt inv = right.Inv();
        return ModInt(SafeMod(left.Value * inv.Value));
    }

    friend ModInt operator/(const ModInt& left, const long long& right)
    {
        return ModInt(SafeMod(left.Value * ModInt(right).Inv().Value));
    }

    friend ModInt operator/(const long long& left, const ModInt& right)
    {
        return ModInt(SafeMod(left * right.Inv().Value));
    }

    ModInt& operator/=(const ModInt& x)
    {
        Value *= x.Inv().Value;
        Value = SafeMod(Value);

        return *this;
    }

    ModInt& operator/=(const long long& x)
    {
        Value *= ModInt(x).Inv().Value;
        Value = SafeMod(Value);

        return *this;
    }

    ModInt& operator++()
    {
        ++Value;
        Value = SafeMod(Value);
        return *this;
    }

    ModInt operator++(int)
    {
        ModInt temp = *this;
        Value++;
        Value = SafeMod(Value);
        return temp;
    }

    ModInt& operator--()
    {
        --Value;
        Value = SafeMod(Value);
        return *this;
    }

    ModInt operator--(int)
    {
        ModInt temp = *this;
        Value--;
        Value = SafeMod(Value);
        return temp;
    }

    inline static ModInt One()
    {
        return ModInt(1L);
    }

    static ModInt Combination(long long n, long long r)
    {
        ModInt c = 1L;
        for (ModInt i = 1; i.Value <= r; i++)
        {
            c = c * (ModInt(n) - i + ModInt::One()) / i;
        }
        return c;
    }

private:
    inline static long long SafeMod(long long a)
    {
        a %= CONST_MOD;
        if (a < 0)
        {
            a += CONST_MOD;
        }
        return a;
    }
};

class ModCache
{
private:
    vector<ModInt> _factorial;
    vector<ModInt> _inverseFactorial;
    vector<ModInt> _inverse;

public:
    ModCache(int max)
    {
        _factorial.resize(max + 1);
        _inverseFactorial.resize(max + 1);
        _inverse.resize(max + 1);

        _factorial[0] = 1;
        _inverseFactorial[0] = 1LL;
        _inverse[1] = 1LL;

        for (long p = 1; p <= max; p++)
        {
            _factorial[p] = _factorial[p - 1] * p;
            if (p > 1)
            {
                _inverse[p] = -(CONST_MOD / p) * _inverse[CONST_MOD % p];
            }
            _inverseFactorial[p] = _inverseFactorial[p - 1] * _inverse[p];
        }
    }

    ModInt Combination(int n, int r)
    {
        if (n < 0 || r < 0 || n < r) return 0;
        return _factorial[n] * (_inverseFactorial[n - r] * _inverseFactorial[r]);
    }

    ModInt Permutation(int n, int r)
    {
        return _factorial[n] * _inverseFactorial[n - r];
    }

    ModInt Factorial(int n)
    {
        return _factorial[n];
    }

    ModInt Inverse(int n)
    {
        return _inverse[n];
    }
};

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, M, K, L;
    cin >> N >> M >> K >> L;

    ModCache cache(N + M * K);

    ModInt ans = 0LL;
    for (int x = L; x <= M; x++)
    {
        ll min1 = 1;
        for (int i = 0; i <= N - 1; i++)
        {
            ans += min1 * cache.Combination(N - 1, i) * (
                    cache.Combination(N - 2 + M * K - x - (M + 1) * i, N - 2)
                -   cache.Combination(N - 2 + M * K - x - (x + 1) * i, N - 2)
            );

            min1 *= -1;
        }
    }

    cout << ans.Value << endl;
}
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