結果

問題 No.2530 Yellow Cards
ユーザー asaringoasaringo
提出日時 2023-11-04 17:45:13
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 590 ms / 2,000 ms
コード長 5,756 bytes
コンパイル時間 2,504 ms
コンパイル使用メモリ 210,152 KB
実行使用メモリ 116,768 KB
最終ジャッジ日時 2024-09-25 22:11:16
合計ジャッジ時間 13,204 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge5
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 348 ms
19,228 KB
testcase_01 AC 353 ms
19,228 KB
testcase_02 AC 337 ms
19,356 KB
testcase_03 AC 344 ms
19,356 KB
testcase_04 AC 344 ms
19,104 KB
testcase_05 AC 343 ms
19,484 KB
testcase_06 AC 347 ms
19,228 KB
testcase_07 AC 573 ms
116,764 KB
testcase_08 AC 567 ms
116,764 KB
testcase_09 AC 565 ms
116,768 KB
testcase_10 AC 566 ms
116,764 KB
testcase_11 AC 590 ms
116,608 KB
testcase_12 AC 589 ms
116,608 KB
testcase_13 AC 573 ms
116,480 KB
testcase_14 AC 494 ms
87,296 KB
testcase_15 AC 441 ms
62,492 KB
testcase_16 AC 446 ms
63,616 KB
testcase_17 AC 511 ms
93,568 KB
testcase_18 AC 417 ms
47,872 KB
testcase_19 AC 365 ms
25,600 KB
testcase_20 AC 372 ms
29,184 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;
#define overload2(a, b, c, ...) c
#define overload3(a, b, c, d, ...) d
#define overload4(a, b, c, d, e ...) e
#define overload5(a, b, c, d, e, f ...) f
#define overload6(a, b, c, d, e, f, g ...) g
#define fast_io ios::sync_with_stdio(false); cin.tie(nullptr);
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
typedef long long ll;
typedef long double ld;
#define chmin(a,b) a = min(a,b);
#define chmax(a,b) a = max(a,b);
#define bit_count(x) __builtin_popcountll(x)
#define leading_zero_count(x) __builtin_clz(x)
#define trailing_zero_count(x) __builtin_ctz(x)
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) a / gcd(a,b) * b
#define rep(...) overload3(__VA_ARGS__, rrep, rep1)(__VA_ARGS__)
#define rep1(i,n) for(int i = 0 ; i < n ; i++)
#define rrep(i,a,b) for(int i = a ; i < b ; i++)
#define repi(it,S) for(auto it = S.begin() ; it != S.end() ; it++)
#define pt(a) cout << a << endl;
#define print(...) printall(__VA_ARGS__);
#define debug(a) cout << #a << " " << a << endl;
#define all(a) a.begin(), a.end()
#define endl "\n";
#define v1(T,n,a) vector<T>(n,a)
#define v2(T,n,m,a) vector<vector<T>>(n,v1(T,m,a))
#define v3(T,n,m,k,a) vector<vector<vector<T>>>(n,v2(T,m,k,a))
#define v4(T,n,m,k,l,a) vector<vector<vector<vector<T>>>>(n,v3(T,m,k,l,a))
template<typename T,typename U>istream &operator>>(istream&is,pair<T,U>&p){is>>p.first>>p.second;return is;}
template<typename T,typename U>ostream &operator<<(ostream&os,const pair<T,U>&p){os<<p.first<<" "<<p.second;return os;}
template<typename T>istream &operator>>(istream&is,vector<T>&v){for(T &in:v){is>>in;}return is;}
template<typename T>ostream &operator<<(ostream&os,const vector<T>&v){for(auto it=v.begin();it!=v.end();){os<<*it<<((++it)!=v.end()?" ":"");}return os;}
template<typename T>istream &operator>>(istream&is,vector<vector<T>>&v){for(T &in:v){is>>in;}return is;}
template<typename T>ostream &operator<<(ostream&os,const vector<vector<T>>&v){for(auto it=v.begin();it!=v.end();){os<<*it<<((++it)!=v.end()?"\n":"");}return os;}
template<typename T>ostream &operator<<(ostream&os,const set<T>&v){for(auto it=v.begin();it!=v.end();){os<<*it<<((++it)!=v.end()?" ":"");}return os;}
template<typename T>ostream &operator<<(ostream&os,const multiset<T>&v){for(auto it=v.begin();it!=v.end();){os<<*it<<((++it)!=v.end()?" ":"");}return os;}
template<class... Args> void printall(Args... args){for(auto i:initializer_list<common_type_t<Args...>>{args...}) cout<<i<<" ";cout<<endl;}

const int mod = 998244353 ;

template< int mod >
struct ModInt {
    int x;

    ModInt() : x(0) {}

    ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

    ModInt &operator+=(const ModInt &p) {
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }

    ModInt &operator-=(const ModInt &p) {
        if((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }

    ModInt &operator*=(const ModInt &p) {
        x = (int) (1LL * x * p.x % mod);
        return *this;
    }

    ModInt &operator/=(const ModInt &p) {
        *this *= p.inverse();
        return *this;
    }

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

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

    ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

    ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

    ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

    bool operator==(const ModInt &p) const { return x == p.x; }

    bool operator!=(const ModInt &p) const { return x != p.x; }

    ModInt inverse() const {
        int a = x, b = mod, u = 1, v = 0, t;
        while(b > 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(u -= t * v, v);
        }
        return ModInt(u);
    }

    ModInt pow(int64_t n) const {
        ModInt ret(1), mul(x);
        while(n > 0) {
            if(n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }

    friend ostream &operator<<(ostream &os, const ModInt &p) {
        return os << p.x;
    }

    friend istream &operator>>(istream &is, ModInt &a) {
        int64_t t;
        is >> t;
        a = ModInt< mod >(t);
        return (is);
    }

    static int get_mod() { return mod; }
};

using modint = ModInt< mod >;

const int MAX_N = 2010101 ;

modint inv[MAX_N+1] ; // (n!)^(p-2) (mod p) を格納
modint fac[MAX_N+1] ; // (n!) (mod p) を格納

modint powmod(modint x , ll n){
    modint res = 1 ;
    while(n > 0){
        if(n & 1) res *= x;
        x *= x;
        n >>= 1 ;
    }
    return res ;
}

// 階乗の逆元(n!)^(-1)のmodを配列に格納
void f(){
    inv[0] = 1 ; inv[1] = 1 ;
    for(ll i = 2 ; i <= MAX_N ; i++){
        inv[i] = powmod(i,mod-2) * inv[i-1];
    }
}

// 階乗のmodを配列に格納
void g(){
    fac[0] = 1 ; fac[1] = 1 ;
    for(ll i = 2 ; i <= MAX_N ; i++){
        fac[i] = fac[i-1] * i;
    }
}

//nCrの計算
modint combination(ll n , ll r){
    if(n < 0 || r < 0 || n < r) return 0 ;
    return fac[n] * inv[n-r] * inv[r];
}

modint permutation(ll n , ll r){
    if(n < 0 || r < 0 || n < r) return 0 ;
    return fac[n] * inv[n-r];
}

void init(){ f() ; g() ; }


void solve(){
    ll n, k;
    cin >> n >> k;
    vector<vector<modint>> dp(k+1,vector<modint>(n+1,0));
    dp[0][0] = 1;
    rep(i,k){
        rep(j,n+1){
            if(j < n) dp[i+1][j+1] += dp[i][j] * (n - j);
            if(j > 0) dp[i+1][j-1] += dp[i][j] * j;
        }
    }
    modint res = 0;
    rep(i,n+1){
        res += dp[k][i] * ((k - i) / 2 + n);
    }
    pt(res/powmod(n,k))
}

int main(){
    fast_io
    init();
    int t = 1;
    // cin >> t;
    rep(i,t) solve();
}
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