結果

問題 No.3206 う し た ウ ニ 木 あ く ん 笑
ユーザー Katu2ou
提出日時 2025-07-18 22:22:49
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 9,301 bytes
コンパイル時間 6,697 ms
コンパイル使用メモリ 334,488 KB
実行使用メモリ 122,704 KB
最終ジャッジ日時 2025-07-18 22:23:01
合計ジャッジ時間 10,375 ms
ジャッジサーバーID
(参考情報)
judge2 / judge3
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 2
other AC * 26 WA * 4
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 #

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;

#define rep2(i, m, n) for (int i = (m); i < (n); ++i)
#define rep(i, n) rep2(i, 0, n)
#define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i)
#define drep(i, n) drep2(i, n, 0)
#define all(...) std::begin(__VA_ARGS__), std::end(__VA_ARGS__)
#define rall(...) std::rbegin(__VA_ARGS__), std::rend(__VA_ARGS__)
#define CLR(a, b) memset((a), (b), sizeof(a))
#define DUMP(x) cout << #x << " = " << (x) << endl;
#define INF (long long)1001001001001001001
#define inf 1001001000
#define MOD 998244353
#define MOD1 1000000007
#define PI 3.14159265358979
#define epsilon 1e-12
#define fcout cout << fixed << setprecision(12)
#define MP make_pair
#define PB push_back
#define fi first
#define se second
#define ERASE(x) x.erase(unique(x.begin(),x.end()),x.end())

using ll = long long;
using ld = long double;
using vi = vector<int>;
using vl = vector<long long>;
using vs = vector<string>;
using vd = vector<double>;
using vld = vector<long double>;
using vb = vector<bool>;
using vpii = vector<pair<int, int>>;
using vpll = vector<pair<long long, long long>>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<long long>>;
using vvd = vector<vector<double>>;
using vvld = vector<vector<long double>>;
using vvb = vector<vector<bool>>;
using vvpii = vector<vector<pair<int,int>>>;
using vvpll = vector<vector<pair<long long,long long>>>;
using vvvi = vector<vector<vector<int>>>;
using vvvl = vector<vector<vector<long long>>>;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
using LL = __int128_t;
using mint = atcoder::modint998244353;
using vmint = vector<mint>;
using vvmint = vector<vector<mint>>;
using vvvmint = vector<vector<vector<mint>>>;

ll gcd(ll x, ll y) {if (x == 0) return y;	return gcd(y%x, x);} 
ll lcm(ll x, ll y) { __int128_t xx,yy; xx=x; yy=y; __int128_t ans=xx * yy / gcd(x, y); ll ans2=ans; return ans2; }
template<typename T>
T POW(T x, ll n){T ret=1;	while(n>0){		if(n&1) ret=ret*x;		x=x*x;		n>>=1;	}	return ret;}
template<typename T>
T modpow(T a, ll n, T p) {	if(n==0) return (T)1;  if (n == 1) return a % p;  if (n % 2 == 1) return (a * modpow(a, n - 1, p)) % p;  T t = modpow(a, n / 2, p);  return (t * t) % p;}
template<typename T>
T modinv(T a, T m) {	if(m==0)return (T)1;	T b = m, u = 1, v = 0;	while (b) {		T t = a / b;		a -= t * b; swap(a, b);		u -= t * v; swap(u, v);	}	u %= m;	if (u < 0) u += m;	return u;}
ll REM(ll a, ll b){ return (a % b + b) % b;}
ll QUO(ll a, ll b){ return (a - REM(a, b)) / b;}
/*
random_device rd;
mt19937 gen(rd());
uniform_int_distribution<> dist1(1, 100); [1,100]
int random_value = dist1(gen);
*/
/*
auto start = chrono::steady_clock::now(); //時間計測の開始
auto now = std::chrono::steady_clock::now(); //現在時刻と開始時刻の差を測定
double elapsed = std::chrono::duration<double>(now - start).count(); //時間をdouble型で取得
*/
/*
const int MAXCOMB=510000;
std::vector<mint> FAC(MAXCOMB), FINV(MAXCOMB), INV(MAXCOMB);
void COMinit() {FAC[0] = FAC[1] = 1;FINV[0] = FINV[1] = 1;INV[1] = 1;for (int i = 2; i < MAXCOMB; i++) {FAC[i] = FAC[i - 1] * i;INV[i] = mint(0) - INV[mint::mod() % i] * (mint::mod() / i);FINV[i] = FINV[i - 1] * INV[i];}}
mint COM(int n, int k) {if (n < k) return 0;if (n < 0 || k < 0) return 0;return FAC[n] * FINV[k] * FINV[n - k];}
*/

template <typename T> inline bool chmax(T &a, T b) { return ((a < b) ? (a = b, true) : (false));}
template <typename T> inline bool chmin(T &a, T b) { return ((a > b) ? (a = b, true) : (false));}
template <class T> T BS(vector<T> &vec, T key) {return lower_bound(vec.begin(), vec.end(), key) - vec.begin();}
template<class T> pair<T,T> RangeBS(vector<T> &vec, T lowv, T highv){auto itr_l = lower_bound(vec.begin(), vec.end(), lowv); auto itr_r = upper_bound(vec.begin(), vec.end(), highv); return make_pair(distance(vec.begin(), itr_l), distance(vec.begin(), itr_r)-1);}
void fail() { cout << "-1\n"; exit(0); } void no() { cout << "No\n"; exit(0); } void yes() { cout << "Yes\n"; exit(0); }
int dx[] = { 1,0,-1,0,1,1,-1,-1 }; int dy[] = { 0,1,0,-1,1,-1,1,-1};
bool range_in(int i, int j, int h, int w){ if(i<0 || j<0 || i>=h || j>=w) return false; return true;} 
int bitcount(int n){n=(n&0x55555555)+(n>>1&0x55555555); n=(n&0x33333333)+(n>>2&0x33333333); n=(n&0x0f0f0f0f)+(n>>4&0x0f0f0f0f); n=(n&0x00ff00ff)+(n>>8&0x00ff00ff); n=(n&0x0000ffff)+(n>>16&0x0000ffff); return n;}

template<typename T>
struct Edge{
    int from, to, index;
    T cost;
    Edge() : from(-1), to(-1), index(-1), cost(0) {}
    Edge(int _to) : from(-1), to(_to), index(-1), cost(0) {}
    Edge(int _to, T _cost) : from(-1), to(_to), index(-1), cost(_cost) {}
    Edge(int _from, int _to, int _index) : from(_from), to(_to), index(_index), cost(0) {}
    Edge(int _from, int _to, int _index, T _cost) 
        : from(_from), to(_to), index(_index), cost(_cost) {}
    bool operator<(const Edge<T>& other) const {
        return cost < other.cost; 
    }
    Edge &operator=(const int &x) {
        to = x;
        return *this;
    }
    operator int() const { return to; }
};
using Graph = vector<vector<int>>; 
template <typename T>
using WGraph = vector<vector<Edge<T>>>; 

/////////////////////////////////////////////////////////////////////////////////////////

template<
    class E, class V,
    E (*merge)(E&, E&),          // 非 const 参照
    E (*e)(),
    E (*put_edge)(V,int),
    V (*put_vertex)(const E&,int)
>
struct RerootingDP {
    struct Edge { int to, idx, xdi; };

    explicit RerootingDP(int n_=0)
        : n(n_), inner_edge_id(0),
          es(2*n-2), start(2*n-2) { if(n==1) es_build(); }

    void add_edge(int u,int v,int idx,int xdi){
        start[inner_edge_id]=u; es[inner_edge_id++]={v,idx,xdi};
        start[inner_edge_id]=v; es[inner_edge_id++]={u,xdi,idx};
        if(inner_edge_id==2*n-2) es_build();
    }

    vector<V> build(int root_=0){
        root=root_;
        vector<V> subdp(n); subdp[0]=put_vertex(e(),0);
        outs.resize(n);

        vector<int> ptr(n+1);
        rep(i,n) ptr[i+1]=start[i+1]-start[i]-1;
        ++ptr[root+1];
        rep(i,n) ptr[i+1]+=ptr[i];

        auto dfs=[&](auto&& self,int v,int p)->void{
            E acc=e();
            for(int i=start[v]; i<start[v+1]; ++i){
                if(es[i].to==p) swap(es[start[v+1]-1],es[i]);
                if(es[i].to==p) continue;
                self(self,es[i].to,v);
                E nxt = put_edge(subdp[es[i].to], es[i].idx);
                outs[ptr[v]++] = nxt;
                acc = merge(acc, nxt);
            }
            subdp[v]=put_vertex(acc,v);
        };
        dfs(dfs,root,-1);
        return subdp;
    }

    vector<V> reroot(){
        vector<E> rev(n,e());
        vector<V> ans(n);

        auto dfs=[&](auto&& self,int v)->void{
            int L=outs_start(v), R=outs_start(v+1), sz=R-L;
            vector<E> suf(sz+1,e());
            for(int i=sz-1;i>=0;--i){
                // outs[L+i] を直接触らない
                E tmp = outs[L+i];
                suf[i]=merge(tmp,suf[i+1]);
            }
            ans[v]=put_vertex(merge(suf[0],rev[v]),v);

            E pref=e();
            for(int i=0;i<sz;++i){
                // pref と suf[i+1] を先に合成
                E tmp1 = merge(pref, suf[i+1]);
                E tmp2 = merge(tmp1, rev[v]);
                V updp = put_vertex(tmp2, v);

                rev[ es[start[v]+i].to ] =
                    put_edge(updp, es[start[v]+i].xdi);

                // pref 更新:outs[L+i] はコピー経由
                E tmp_out = outs[L+i];
                pref = merge(pref, tmp_out);

                self(self, es[start[v]+i].to);
            }
        };
        dfs(dfs,root);
        return ans;
    }

private:
    int n, root, inner_edge_id;
    vector<E> outs;
    vector<Edge> es;
    vector<int>  start;

    int outs_start(int v){ int r=start[v]-v; if(root<v) ++r; return r; }

    void es_build(){
        vector<Edge> nes(2*n-2); vector<int> nst(n+2);
        rep(i,2*n-2) ++nst[start[i]+2];
        rep(i,n) nst[i+1]+=nst[i];
        rep(i,2*n-2) nes[nst[start[i]+1]++]=es[i];
        swap(es,nes); swap(start,nst);
    }
};

vi merge(vi& a, vi& b)
{
    if(a.size() < b.size()) swap(a,b);         
    a.insert(a.end(), b.begin(), b.end());      
    return std::move(a);                       
}

vi e(){ return {}; }

vi put_edge(pii v, int I){
    return { v.first + 1 };
}

pii put_vertex(const vi& e, int I){
    if(e.empty()) return {0,0};
    vi v=e;                                    
    sort(v.begin(), v.end(), greater<int>());
    int now=inf, best=0;
    rep(i,(int)v.size()){
        now = min(now, v[i]);
        best = max(best, (i+1)*now);
    }
    return {v[0], best};
}

void solve(){
    int n;
    cin>>n;
    struct RerootingDP<vi, pii, merge, e, put_edge, put_vertex> dp(n);
    rep(i,n-1){
        int a,b;
        cin>>a>>b;
        a--;
        b--;
        dp.add_edge(a,b,0,0);
    }
    dp.build(0);
    vpii res = dp.reroot();
    int ans = 0;
    rep(i,res.size())chmax(ans,res[i].se);
    cout<<ans+1<<endl;
}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	cout<<fixed<<setprecision(20);
	int TT; TT = 1; //cin >> TT;
	while(TT--) solve();
}
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