結果
問題 | No.1302 Random Tree Score |
ユーザー |
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提出日時 | 2020-12-31 18:33:16 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 13 ms / 3,000 ms |
コード長 | 4,516 bytes |
コンパイル時間 | 1,245 ms |
コンパイル使用メモリ | 126,924 KB |
最終ジャッジ日時 | 2025-01-17 08:47:50 |
ジャッジサーバーID (参考情報) |
judge2 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 14 |
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;typedef unsigned int ui;const ll mod = 998244353;const ll INF = (ll)1000000007 * 1000000007;typedef pair<int, int> P;#define stop char nyaa;cin>>nyaa;#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--)#define rep1(i,n) for(int i=1;i<=n;i++)#define per1(i,n) for(int i=n;i>=1;i--)#define Rep1(i,sta,n) for(int i=sta;i<=n;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];}};int n;ModFac MF(500010);void solve(){cin >> n;modint ans=0;modint pow=1;rep(i,n-1){ans+=MF.comb(n,n-2-i)*pow*MF.inv_factorial(i);pow*=n;}ans*=MF.factorial(n-2);ans/=((modint)n).power(n-2);cout << ans << endl;}int main(){ios::sync_with_stdio(false);cin.tie(0);cout << fixed << setprecision(50);solve();}