結果
| 問題 | No.2381 Gift Exchange Party |
| ユーザー |
 asaringo
|
| 提出日時 | 2023-07-14 22:37:22 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 372 ms / 2,000 ms |
| コード長 | 5,393 bytes |
| コンパイル時間 | 2,339 ms |
| コンパイル使用メモリ | 199,052 KB |
| 最終ジャッジ日時 | 2025-02-15 14:22:25 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 22 |
ソースコード
#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()?" ":"");}returnos;}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()?" ":"");}returnos;}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_ioint t = 1;// cin >> t;rep(i,t) solve();}