結果

問題 No.2388 At Least K-Characters
ユーザー PAKACHUPAKACHU
提出日時 2023-07-22 02:50:01
言語 C++17(clang)
(17.0.6 + boost 1.83.0)
結果
AC  
実行時間 262 ms / 4,000 ms
コード長 3,857 bytes
コンパイル時間 4,150 ms
コンパイル使用メモリ 136,604 KB
実行使用メモリ 93,448 KB
最終ジャッジ日時 2023-09-18 13:05:05
合計ジャッジ時間 11,810 ms
ジャッジサーバーID
（参考情報） 		judge13 / judge12
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 31 ms
18,612 KB
testcase_01 AC 31 ms
18,660 KB
testcase_02 AC 31 ms
18,640 KB
testcase_03 AC 31 ms
18,624 KB
testcase_04 AC 31 ms
18,612 KB
testcase_05 AC 31 ms
18,524 KB
testcase_06 AC 30 ms
18,672 KB
testcase_07 AC 31 ms
18,584 KB
testcase_08 AC 31 ms
18,616 KB
testcase_09 AC 31 ms
18,628 KB
testcase_10 AC 31 ms
18,616 KB
testcase_11 AC 32 ms
18,836 KB
testcase_12 AC 31 ms
18,636 KB
testcase_13 AC 32 ms
19,144 KB
testcase_14 AC 31 ms
19,056 KB
testcase_15 AC 32 ms
19,064 KB
testcase_16 AC 236 ms
93,364 KB
testcase_17 AC 191 ms
93,408 KB
testcase_18 AC 248 ms
93,404 KB
testcase_19 AC 247 ms
93,376 KB
testcase_20 AC 247 ms
93,428 KB
testcase_21 AC 261 ms
93,360 KB
testcase_22 AC 262 ms
93,424 KB
testcase_23 AC 257 ms
93,376 KB
testcase_24 AC 261 ms
93,384 KB
testcase_25 AC 250 ms
93,428 KB
testcase_26 AC 256 ms
93,448 KB
testcase_27 AC 255 ms
93,408 KB
testcase_28 AC 255 ms
93,432 KB
testcase_29 AC 254 ms
93,380 KB
testcase_30 AC 254 ms
93,432 KB
testcase_31 AC 253 ms
93,356 KB
testcase_32 AC 250 ms
93,328 KB
testcase_33 AC 251 ms
93,420 KB
testcase_34 AC 254 ms
93,436 KB
testcase_35 AC 257 ms
93,352 KB
testcase_36 AC 260 ms
93,400 KB
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 # 

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;
typedef long double ld;
int dx[8] = { 1, 0, -1, 0, 1, 1, -1, -1 }, dy[8] = { 0, 1, 0, -1, 1, -1, 1, -1 };
const long long mod = 998244353;
const ll inf = 1LL << 60;
const int INF = 1e9 + 1;

template <int MOD>
struct ModInt {
    static const int Mod = MOD;
    unsigned x;
    ModInt()
        : x(0)
    {
    }
    ModInt(signed sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    ModInt(signed long long sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    int get() const { return (int)x; }
    ModInt& operator+=(ModInt that)
    {
        if ((x += that.x) >= MOD)
            x -= MOD;
        return *this;
    }
    ModInt& operator-=(ModInt that)
    {
        if ((x += MOD - that.x) >= MOD)
            x -= MOD;
        return *this;
    }
    ModInt& operator*=(ModInt that)
    {
        x = (unsigned long long)x * that.x % MOD;
        return *this;
    }
    ModInt& operator/=(ModInt that) { return *this *= that.inverse(); }
    ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
    ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
    ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
    ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
    ModInt inverse() const
    {
        long long a = x, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b;
            std::swap(a, b);
            u -= t * v;
            std::swap(u, v);
        }
        return ModInt(u);
    }
    bool operator==(ModInt that) const { return x == that.x; }
    bool operator!=(ModInt that) const { return x != that.x; }
    ModInt operator-() const
    {
        ModInt t;
        t.x = x == 0 ? 0 : Mod - x;
        return t;
    }
};
template <int MOD>
ostream& operator<<(ostream& st, const ModInt<MOD> a)
{
    st << a.get();
    return st;
};
template <int MOD>
ModInt<MOD> operator^(ModInt<MOD> a, unsigned long long k)
{
    ModInt<MOD> r = 1;
    while (k) {
        if (k & 1)
            r *= a;
        a *= a;
        k >>= 1;
    }
    return r;
}

template <typename T, int FAC_MAX>
struct Comb {
    vector<T> fac, ifac;
    Comb()
    {
        fac.resize(FAC_MAX, 1);
        ifac.resize(FAC_MAX, 1);
        for (int i = 1; i < FAC_MAX; i++)
            fac[i] = fac[i - 1] * i;
        ifac[FAC_MAX - 1] = T(1) / fac[FAC_MAX - 1];
        for (int i = FAC_MAX - 2; i >= 1; i--)
            ifac[i] = ifac[i + 1] * T(i + 1);
    }
    T aPb(int a, int b)
    {
        if (b < 0 || a < b)
            return T(0);
        return fac[a] * ifac[a - b];
    }
    T aCb(int a, int b)
    {
        if (b < 0 || a < b)
            return T(0);
        return fac[a] * ifac[a - b] * ifac[b];
    }
    T nHk(int n, int k)
    {
        if (n == 0 && k == 0)
            return T(1);
        if (n <= 0 || k < 0)
            return 0;
        return aCb(n + k - 1, k);
    }
};
typedef ModInt<998244353> mint;
Comb<mint, 2000009> comb;

int main()
{
    int n, m, k;
    cin >> n >> m >> k;
    string s;
    cin >> s;
    set<int> st;
    vector<vector<mint>> dp(m + 1, vector<mint>(27));
    

    mint ans = 0;
    for (int i = 0; i < m; i++) {
        for (int j = 26; j >= 0; j--) {
            if (j < 26)
                dp[i + 1][j + 1] += dp[i][j] * (26 - j);
            dp[i + 1][j] += dp[i][j] * j;
        }

        if (i < n) {
            int a = s[i] - 'a';
            for (int j = 0; j < a; j++) {
                dp[i + 1][(int)st.size() + !st.count(j)] += 1;
            }
            st.insert(a);
        }

        for (int j = k; j <= 26; j++)
            ans += dp[i + 1][j];
        if ((int)st.size() >= k and i < n - 1)
            ans += 1;
    }
    cout << ans << endl;

}
0