結果

問題 No.2381 Gift Exchange Party
ユーザー asaringoasaringo
提出日時 2023-07-14 22:37:22
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 364 ms / 2,000 ms
コード長 5,393 bytes
コンパイル時間 2,314 ms
コンパイル使用メモリ 203,180 KB
実行使用メモリ 19,312 KB
最終ジャッジ日時 2023-10-14 12:53:31
合計ジャッジ時間 12,685 ms
ジャッジサーバーID
（参考情報） 		judge11 / judge15
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 359 ms
19,056 KB
testcase_01 AC 358 ms
19,076 KB
testcase_02 AC 360 ms
19,048 KB
testcase_03 AC 360 ms
19,096 KB
testcase_04 AC 360 ms
19,076 KB
testcase_05 AC 360 ms
19,168 KB
testcase_06 AC 361 ms
19,076 KB
testcase_07 AC 361 ms
19,184 KB
testcase_08 AC 360 ms
19,052 KB
testcase_09 AC 360 ms
19,096 KB
testcase_10 AC 359 ms
19,168 KB
testcase_11 AC 362 ms
19,096 KB
testcase_12 AC 360 ms
19,076 KB
testcase_13 AC 363 ms
19,080 KB
testcase_14 AC 360 ms
19,072 KB
testcase_15 AC 360 ms
19,052 KB
testcase_16 AC 360 ms
19,208 KB
testcase_17 AC 361 ms
19,076 KB
testcase_18 AC 361 ms
19,312 KB
testcase_19 AC 361 ms
19,084 KB
testcase_20 AC 364 ms
19,116 KB
testcase_21 AC 361 ms
19,272 KB
testcase_22 AC 362 ms
19,156 KB
testcase_23 AC 360 ms
19,060 KB
testcase_24 AC 360 ms
19,060 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 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(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 debug(a) cout << #a << " " << a << endl;
#define all(a) a.begin(), a.end()
#define endl "\n";
#define v1(n,a) vector<ll>(n,a)
#define v2(n,m,a) vector<vector<ll>>(n,v1(m,a))
#define v3(n,m,k,a) vector<vector<vector<ll>>>(n,v2(m,k,a))
#define v4(n,m,k,l,a) vector<vector<vector<vector<ll>>>>(n,v3(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;}

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, p;
    cin >> n >> p;
    ll N = n;
    init();
    modint res = 1;
    rep(i,n) res *= (n - i);
    if(p > n){
        pt(res - 1)
        return;
    }
    modint pr = 1;
    rep(i,p-1) pr *= (p - i - 1);
    modint sum = 0;
    modint val = 1;
    int cnt = 1;
    while(n > 0){
        ll k = (cnt * p - 1);
        rep(i,p-1) val *= k - i;
        modint pls = val * combination(N,cnt*p);
        sum += pls;
        n -= p;
        cnt++;
    }
    pt(res - sum - 1);
}

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