結果

問題 No.3373 Partial Complement Tree
コンテスト
ユーザー GOTKAKO
提出日時 2025-11-21 21:35:13
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 216 ms / 2,000 ms
コード長 3,740 bytes
コンパイル時間 1,825 ms
コンパイル使用メモリ 203,344 KB
実行使用メモリ 51,508 KB
最終ジャッジ日時 2025-11-21 21:35:20
合計ジャッジ時間 6,130 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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ファイルパターン 結果
sample AC * 1
other AC * 24
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;

//入力が必ず-mod<=a<modの時.
template<const int mod> //mod<2^30.
struct modint{ //mod変更が不可能.
    public:
    long long v;
    static void setmod(int m){} //飾り.
    static constexpr long long getmod(){return mod;}
    modint():v(0){}
    template<typename T>
    modint(T a):v(a){if(v < 0) v += mod;}
    long long val()const{return v;}
 
    modint &operator=(const modint &b) = default;
    modint &operator+()const{return (*this);}
    modint operator-()const{return modint(0)-(*this);}
    modint operator+(const modint b)const{return modint(v)+=b;}
    modint operator-(const modint b)const{return modint(v)-=b;}
    modint operator*(const modint b)const{return modint(v)*=b;}
    modint operator/(const modint b)const{return modint(v)/=b;}
    modint &operator+=(const modint b){
        v += b.v; if(v >= mod) v -= mod;
        return *this;
    }
    modint &operator-=(const modint b){
        v -= b.v; if(v < 0) v += mod; 
        return *this;
    }   
    modint &operator*=(const modint b){v = v*b.v%mod; return *this;}
    modint &operator/=(modint b){ //b!=0 mod素数が必須.
        assert(b.v != 0);
        (*this) *= b.pow(mod-2);
        return *this;
    }
    modint pow(long long n)const{
        modint ret = 1,p = v;
        if(n < 0) p = p.inv(),n = -n;
        while(n){
            if(n&1) ret *= p;
            p *= p; n >>= 1;
        }
        return ret;
    }
    modint inv()const{return pow(mod-2);} //素数mod必須.
 
    modint &operator++(){*this += 1; return *this;}
    modint &operator--(){*this -= 1; return *this;}
    modint operator++(int){modint ret = *this; *this += 1; return ret;}
    modint operator--(int){modint ret = *this; *this -= 1; return ret;}
    friend bool operator==(const modint a,const modint b){return a.v==b.v;}
    friend bool operator!=(const modint a,const modint b){return a.v!=b.v;}
    friend bool operator<(const modint a,const modint b){return a.v<b.v;}
    friend bool operator<=(const modint a,const modint b){return a.v<=b.v;}
    friend bool operator>=(const modint a,const modint b){return a.v>=b.v;}
    friend bool operator>(const modint a,const modint b){return a.v>b.v;}
    friend ostream &operator<<(ostream &os,const modint a){return os<<a.v;}
    friend istream &operator>>(istream &is,modint &a){ //入力はmodをとってくれる.
        long long x; is >> x; x %= mod;
        a = modint(x); return is;
    }
};
using mint = modint<998244353>; const long long mod = 998244353;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int T; cin >> T;
    while(T--){
        int N; cin >> N;
        vector<vector<int>> Graph(N);
        for(int i=0; i<N-1; i++){
            int u,v; cin >> u >> v;
            u--; v--;
            Graph.at(u).push_back(v);
            Graph.at(v).push_back(u);
        }

        mint answer = 0;
        auto dfs = [&](auto dfs,int pos,int back) -> pair<int,int> {
            
            vector<int> Two;
            int two = 0,three = 0;
            vector<mint> dp(4);
            dp.at(0) = 1;
            for(auto to : Graph.at(pos)){
                if(to == back) continue;
                auto [k2,k3] = dfs(dfs,to,pos);
                three += k2,two++;
                answer += k3;
                vector<mint> next = dp;
                for(int i=0; i<4; i++){
                    if(i == 0 || i == 2) next.at(i+1) += dp.at(i);
                    if(i == 0 || i == 1) next.at(i+2) += dp.at(i)*k2;
                }
                swap(dp,next);
            }
            answer += dp.at(3);
            return {two,three};
        };
        dfs(dfs,0,-1);
        cout << answer << "\n";
    }
}
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