結果
問題 |
No.1392 Don't be together
|
ユーザー |
![]() |
提出日時 | 2021-02-13 21:28:52 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 546 ms / 2,000 ms |
コード長 | 5,609 bytes |
コンパイル時間 | 2,169 ms |
コンパイル使用メモリ | 138,324 KB |
最終ジャッジ日時 | 2025-01-18 20:15:00 |
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 * 27 |
ソースコード
#include<iostream> #include<array> #include<string> #include<cstdio> #include<vector> #include<cmath> #include<algorithm> #include<functional> #include<iomanip> #include<queue> #include<ciso646> #include<random> #include<map> #include<set> #include<complex> #include<bitset> #include<stack> #include<unordered_map> #include<utility> #include<tuple> #include<cassert> using namespace std; typedef long long ll; const ll mod = 998244353; const ll INF = (ll)1000000007 * 1000000007; typedef pair<int, int> P; #define rep(i,n) for(int i=0;i<n;i++) #define per(i,n) for(int i=n-1;i>=0;i--) #define Rep(i,sta,n) for(int i=sta;i<n;i++) #define Per(i,sta,n) for(int i=n-1;i>=sta;i--) typedef long double ld; const ld eps = 1e-8; const ld pi = acos(-1.0); typedef pair<ll, ll> LP; int dx[4]={1,-1,0,0}; int dy[4]={0,0,1,-1}; template<class T>bool chmax(T &a, const T &b) {if(a<b){a=b;return 1;}return 0;} template<class T>bool chmin(T &a, const T &b) {if(b<a){a=b;return 1;}return 0;} template<int mod> struct ModInt { long long x; static constexpr int MOD = mod; ModInt() : x(0) {} ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} explicit operator int() const {return x;} 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; } ModInt operator%(const ModInt &p) const { return ModInt(0); } 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; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } ModInt power(long long n) const { ModInt ret(1), mul(x); while(n > 0) { if(n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } ModInt power(const ModInt p) const{ return ((ModInt)x).power(p.x); } friend ostream &operator<<(ostream &os, const ModInt<mod> &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt<mod> &a) { long long x; is >> x; a = ModInt<mod>(x); return (is); } }; using modint = ModInt<mod>; struct ModFac{ public: vector<modint> f,i_f; int n; ModFac(int n_){ n=n_; f.resize(n+1,1); i_f.resize(n+1,1); for(int i=0;i<n;i++){ f[i+1]=f[i]*(modint)(i+1); } i_f[n]=f[n].power(mod-2); for(int i=n-1;i>=0;i--){ i_f[i]=i_f[i+1]*(modint)(i+1); } } ModFac(modint n_){ n=(int)n_; f.resize(n+1,1); i_f.resize(n+1,1); for(int i=0;i<n;i++){ f[i+1]=f[i]*(modint)(i+1); } i_f[n]=f[n].power(mod-2); for(int i=n-1;i>=0;i--){ i_f[i]=i_f[i+1]*(modint)(i+1); } } modint factorial(int x){ //cout << f.size() << endl; return f[x]; } modint inv_factorial(int x){ return i_f[x]; } modint comb(int m,int k){ if (m<0 or k<0) return 0; if (m<k) return 0; return f[m]*i_f[k]*i_f[m-k]; } }; ModFac MF(500010); int n,m; int p[5010]; vector<modint> f[5010];modint F[5010],S[5010][5010]; bool visited[5010]; vector<int> cs; vector<modint> calc(vector<modint> &f,map<int,modint> &g){ vector<modint> res(n+1,0); for(auto p:g){ rep(i,n+1){ if(i-p.first>=0) res[i]+=f[i-p.first]*p.second; } } return res; } void solve(){ cin >> n >> m; rep(i,n+1){ rep(j,i){ S[i][j]=S[i-1][j-1]+(modint)j*S[i-1][j]; } S[i][i]=1; } rep(i,n){ cin >> p[i];p[i]--; } rep(i,n){ if(visited[i]) continue; int s=i,c=1; while(i!=p[s]){ s=p[s]; c++; visited[s]=true; } cs.push_back(c); } int v=cs.size(); f[0]=vector<modint>(n+1,0);f[0][0]=1; rep(i,v){ //cout << cs[i] << endl; map<int,modint> g; if(cs[i]==1){ g[1]=-1; } else if(cs[i]%2){ g[cs[i]]=1; g[1]=-1; } else{ g[cs[i]]=1; g[1]=1; } f[i+1]=calc(f[i],g); } rep(i,n+1){ rep(j,i+1){ if((i-j)%2)F[j]-=MF.comb(i,j)*f[v][i]; else F[j]+=MF.comb(i,j)*f[v][i]; } } // rep(i,n+1){ // cout << i << " " << f[v][i] << " " << F[i] << endl; // } modint ans=0; rep(i,n+1){ //cout << i << " " << S[i][m] << " " << F[i] << endl; ans+=S[i][m]*F[i]; } cout << ans << endl; } int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(50); solve(); }