結果

問題 No.3194 Do Optimize Your Solution
ユーザー noya2
提出日時 2025-06-23 03:12:50
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
TLE  
(最新)
AC  
(最初)
実行時間 -
コード長 26,017 bytes
コンパイル時間 4,487 ms
コンパイル使用メモリ 326,796 KB
実行使用メモリ 66,668 KB
最終ジャッジ日時 2025-06-27 20:51:09
合計ジャッジ時間 31,142 ms
ジャッジサーバーID
(参考情報)
judge3 / judge5
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 * 16 TLE * 1
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 #

#line 1 "c.cpp"

#line 2 "/Users/noya2/Desktop/Noya2_library/template/template.hpp"
using namespace std;

#include<bits/stdc++.h>
#line 1 "/Users/noya2/Desktop/Noya2_library/template/inout_old.hpp"
namespace noya2 {

template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p){
    os << p.first << " " << p.second;
    return os;
}
template <typename T, typename U>
istream &operator>>(istream &is, pair<T, U> &p){
    is >> p.first >> p.second;
    return is;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v){
    int s = (int)v.size();
    for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i];
    return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v){
    for (auto &x : v) is >> x;
    return is;
}

void in() {}
template <typename T, class... U>
void in(T &t, U &...u){
    cin >> t;
    in(u...);
}

void out() { cout << "\n"; }
template <typename T, class... U, char sep = ' '>
void out(const T &t, const U &...u){
    cout << t;
    if (sizeof...(u)) cout << sep;
    out(u...);
}

template<typename T>
void out(const vector<vector<T>> &vv){
    int s = (int)vv.size();
    for (int i = 0; i < s; i++) out(vv[i]);
}

struct IoSetup {
    IoSetup(){
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(15);
        cerr << fixed << setprecision(7);
    }
} iosetup_noya2;

} // namespace noya2
#line 1 "/Users/noya2/Desktop/Noya2_library/template/const.hpp"
namespace noya2{

const int iinf = 1'000'000'007;
const long long linf = 2'000'000'000'000'000'000LL;
const long long mod998 =  998244353;
const long long mod107 = 1000000007;
const long double pi = 3.14159265358979323;
const vector<int> dx = {0,1,0,-1,1,1,-1,-1};
const vector<int> dy = {1,0,-1,0,1,-1,-1,1};
const string ALP = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string alp = "abcdefghijklmnopqrstuvwxyz";
const string NUM = "0123456789";

void yes(){ cout << "Yes\n"; }
void no(){ cout << "No\n"; }
void YES(){ cout << "YES\n"; }
void NO(){ cout << "NO\n"; }
void yn(bool t){ t ? yes() : no(); }
void YN(bool t){ t ? YES() : NO(); }

} // namespace noya2
#line 2 "/Users/noya2/Desktop/Noya2_library/template/utils.hpp"

#line 6 "/Users/noya2/Desktop/Noya2_library/template/utils.hpp"

namespace noya2{

unsigned long long inner_binary_gcd(unsigned long long a, unsigned long long b){
    if (a == 0 || b == 0) return a + b;
    int n = __builtin_ctzll(a); a >>= n;
    int m = __builtin_ctzll(b); b >>= m;
    while (a != b) {
        int mm = __builtin_ctzll(a - b);
        bool f = a > b;
        unsigned long long c = f ? a : b;
        b = f ? b : a;
        a = (c - b) >> mm;
    }
    return a << std::min(n, m);
}

template<typename T> T gcd_fast(T a, T b){ return static_cast<T>(inner_binary_gcd(std::abs(a),std::abs(b))); }

long long sqrt_fast(long long n) {
    if (n <= 0) return 0;
    long long x = sqrt(n);
    while ((x + 1) * (x + 1) <= n) x++;
    while (x * x > n) x--;
    return x;
}

template<typename T> T floor_div(const T n, const T d) {
    assert(d != 0);
    return n / d - static_cast<T>((n ^ d) < 0 && n % d != 0);
}

template<typename T> T ceil_div(const T n, const T d) {
    assert(d != 0);
    return n / d + static_cast<T>((n ^ d) >= 0 && n % d != 0);
}

template<typename T> void uniq(std::vector<T> &v){
    std::sort(v.begin(),v.end());
    v.erase(unique(v.begin(),v.end()),v.end());
}

template <typename T, typename U> inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; }

template <typename T, typename U> inline bool chmax(T &x, U y) { return (x < y) ? (x = y, true) : false; }

template<typename T> inline bool range(T l, T x, T r){ return l <= x && x < r; }

} // namespace noya2
#line 8 "/Users/noya2/Desktop/Noya2_library/template/template.hpp"

#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define repp(i,m,n) for (int i = (m); i < (int)(n); i++)
#define reb(i,n) for (int i = (int)(n-1); i >= 0; i--)
#define all(v) (v).begin(),(v).end()

using ll = long long;
using ld = long double;
using uint = unsigned int;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pil = pair<int,ll>;
using pli = pair<ll,int>;

namespace noya2{

/* ~ (. _________ . /) */

}

using namespace noya2;


#line 3 "c.cpp"

#line 2 "fastio.hpp"

#line 4 "fastio.hpp"

namespace nachia{

struct CInStream{
private:
	static const unsigned int INPUT_BUF_SIZE = 1 << 17;
	unsigned int p = INPUT_BUF_SIZE;
	static char Q[INPUT_BUF_SIZE];
public:
	using MyType = CInStream;
	char seekChar(){
		if(p == INPUT_BUF_SIZE){
			size_t len = fread(Q, 1, INPUT_BUF_SIZE, stdin);
			if(len != INPUT_BUF_SIZE) Q[len] = '\0';
			p = 0;
		}
		return Q[p];
	}
	void skipSpace(){ while(isspace(seekChar())) p++; }
private:
	template<class T, int sp = 1>
	T nextUInt(){
		if constexpr (sp) skipSpace();
		T buf = 0;
		while(true){
			char tmp = seekChar();
			if('9' < tmp || tmp < '0') break;
			buf = buf * 10 + (tmp - '0');
			p++;
		}
		return buf;
	}
public:
	uint32_t nextU32(){ return nextUInt<uint32_t>(); }
	int32_t nextI32(){
		skipSpace();
		if(seekChar() == '-'){
			p++; return (int32_t)(-nextUInt<uint32_t, 0>());
		}
		return (int32_t)nextUInt<uint32_t, 0>();
	}
	uint64_t nextU64(){ return nextUInt<uint64_t>();}
	int64_t nextI64(){
		skipSpace();
		if(seekChar() == '-'){
			p++; return (int64_t)(-nextUInt<int64_t, 0>());
		}
		return (int64_t)nextUInt<int64_t, 0>();
	}
	template<class T>
	T nextInt(){
		skipSpace();
		if(seekChar() == '-'){
			p++;
			return - nextUInt<T, 0>();
		}
		return nextUInt<T, 0>();
	}
	char nextChar(){ skipSpace(); char buf = seekChar(); p++; return buf; }
	std::string nextToken(){
		skipSpace();
		std::string buf;
		while(true){
			char ch = seekChar();
			if(isspace(ch) || ch == '\0') break;
			buf.push_back(ch);
			p++;
		}
		return buf;
	}
	MyType& operator>>(unsigned int& dest){ dest = nextU32(); return *this; }
	MyType& operator>>(int& dest){ dest = nextI32(); return *this; }
	MyType& operator>>(unsigned long& dest){ dest = nextU64(); return *this; }
	MyType& operator>>(long& dest){ dest = nextI64(); return *this; }
	MyType& operator>>(unsigned long long& dest){ dest = nextU64(); return *this; }
	MyType& operator>>(long long& dest){ dest = nextI64(); return *this; }
	MyType& operator>>(std::string& dest){ dest = nextToken(); return *this; }
	MyType& operator>>(char& dest){ dest = nextChar(); return *this; }
} ncin;

struct FastOutputTable{
	char LZ[1000][4] = {};
	char NLZ[1000][4] = {};
	constexpr FastOutputTable(){
		using u32 = uint_fast32_t;
		for(u32 d=0; d<1000; d++){
			LZ[d][0] = ('0' + d / 100 % 10);
			LZ[d][1] = ('0' + d /  10 % 10);
			LZ[d][2] = ('0' + d /   1 % 10);
			LZ[d][3] = '\0';
		}
		for(u32 d=0; d<1000; d++){
			u32 i = 0;
			if(d >= 100) NLZ[d][i++] = ('0' + d / 100 % 10);
			if(d >=  10) NLZ[d][i++] = ('0' + d /  10 % 10);
			if(d >=   1) NLZ[d][i++] = ('0' + d /   1 % 10);
			NLZ[d][i++] = '\0';
		}
	}
};

struct COutStream{
private:
	using u32 = uint32_t;
	using u64 = uint64_t;
	using MyType = COutStream;
	static const u32 OUTPUT_BUF_SIZE = 1 << 17;
	static char Q[OUTPUT_BUF_SIZE];
	static constexpr FastOutputTable TB = FastOutputTable();
	u32 p = 0;
	static constexpr u32 P10(u32 d){ return d ? P10(d-1)*10 : 1; }
	static constexpr u64 P10L(u32 d){ return d ? P10L(d-1)*10 : 1; }
	template<class T, class U> static void Fil(T& m, U& l, U x){ m = l/x; l -= m*x; }
public:
	void next_dig9(u32 x){
		u32 y;
		Fil(y, x, P10(6));
		nextCstr(TB.LZ[y]);
		Fil(y, x, P10(3));
		nextCstr(TB.LZ[y]); nextCstr(TB.LZ[x]);
	}
	void nextChar(char c){
		Q[p++] = c;
		if(p == OUTPUT_BUF_SIZE){ fwrite(Q, p, 1, stdout); p = 0; }
	}
	void nextEoln(){ nextChar('\n'); }
	void nextCstr(const char* s){ while(*s) nextChar(*(s++)); }
	void nextU32(uint32_t x){
		u32 y = 0;
		if(x >= P10(9)){
			Fil(y, x, P10(9));
			nextCstr(TB.NLZ[y]); next_dig9(x);
		}
		else if(x >= P10(6)){
			Fil(y, x, P10(6));
			nextCstr(TB.NLZ[y]);
			Fil(y, x, P10(3));
			nextCstr(TB.LZ[y]); nextCstr(TB.LZ[x]);
		}
		else if(x >= P10(3)){
			Fil(y, x, P10(3));
			nextCstr(TB.NLZ[y]); nextCstr(TB.LZ[x]);
		}
		else if(x >= 1) nextCstr(TB.NLZ[x]);
		else nextChar('0');
	}
	void nextI32(int32_t x){
		if(x >= 0) nextU32(x);
		else{ nextChar('-'); nextU32((u32)-x); }
	}
	void nextU64(uint64_t x){
		u32 y = 0;
		if(x >= P10L(18)){
			Fil(y, x, P10L(18));
			nextU32(y);
			Fil(y, x, P10L(9));
			next_dig9(y); next_dig9(x);
		}
		else if(x >= P10L(9)){
			Fil(y, x, P10L(9));
			nextU32(y); next_dig9(x);
		}
		else nextU32(x);
	}
	void nextI64(int64_t x){
		if(x >= 0) nextU64(x);
		else{ nextChar('-'); nextU64((u64)-x); }
	}
	template<class T>
	void nextInt(T x){
		if(x < 0){ nextChar('-'); x = -x; }
		if(!(0 < x)){ nextChar('0'); return; }
		std::string buf;
		while(0 < x){
			buf.push_back('0' + (int)(x % 10));
			x /= 10;
		}
		for(int i=(int)buf.size()-1; i>=0; i--){
			nextChar(buf[i]);
		}
	}
	void writeToFile(bool flush = false){
		fwrite(Q, p, 1, stdout);
		if(flush) fflush(stdout);
		p = 0;
	}
	COutStream(){ Q[0] = 0; }
	~COutStream(){ writeToFile(); }
	MyType& operator<<(unsigned int tg){ nextU32(tg); return *this; }
	MyType& operator<<(unsigned long tg){ nextU64(tg); return *this; }
	MyType& operator<<(unsigned long long tg){ nextU64(tg); return *this; }
	MyType& operator<<(int tg){ nextI32(tg); return *this; }
	MyType& operator<<(long tg){ nextI64(tg); return *this; }
	MyType& operator<<(long long tg){ nextI64(tg); return *this; }
	MyType& operator<<(const std::string& tg){ nextCstr(tg.c_str()); return *this; }
	MyType& operator<<(const char* tg){ nextCstr(tg); return *this; }
	MyType& operator<<(char tg){ nextChar(tg); return *this; }
} ncout;

char CInStream::Q[INPUT_BUF_SIZE];
char COutStream::Q[OUTPUT_BUF_SIZE];

} // namespace nachia
#line 5 "c.cpp"

struct fast_lca {
    int n;
    std::vector<int> down, dep;
    std::vector<int> a, pre, suf;
    std::vector<std::vector<int>> st;
    static constexpr int LG = 4;
    static constexpr int MASK = (1 << LG) - 1;
    fast_lca () {}
    fast_lca (const std::vector<int> &par) : n(par.size()), down(n), dep(n), a(n) {
        assert(n >= 1);
        // subtree size - 1
        for (int i = n - 1; i >= 1; i--){
            down[par[i]] += down[i] + 1;
        }
        // euler tour time
        for (int i = 1; i < n; i++){
            down[i] = std::exchange(down[par[i]], down[par[i]] - down[i] - 1);
            dep[i] = dep[par[i]] + 1;
        }
        // build a, pre, suf
        for (int i = 1; i < n; i++){
            a[down[i] - 1] = par[i];
        }
        pre = suf = a;
        for (int i = 1; i < n; i++){
            if (i & MASK){
                if (pre[i] > pre[i - 1]){
                    pre[i] = pre[i - 1];
                }
            }
        }
        for (int i = n - 1; i >= 1; i--){
            if (i & MASK){
                if (suf[i - 1] > suf[i]){
                    suf[i - 1] = suf[i];
                }
            }
        }
        // build st
        int n2 = n >> LG;
        int lg = (n2 <= 1 ? 1 : std::bit_width<uint32_t>(n2 - 1));
        st.resize(lg);
        st[0].resize(n2);
        for (int i = 0; i < n2; i++){
            st[0][i] = suf[i << LG];
        }
        for (int d = 0; d < lg - 1; d++){
            int nsz = (int)(st[d].size()) - (1 << d);
            st[d + 1].resize(nsz);
            for (int i = 0; i < nsz; i++){
                int x = st[d][i];
                int y = st[d][i + (1 << d)];
                st[d + 1][i] = (x < y ? x : y);
            }
        }
    }
    int st_prod(int l, int r) const {
        if (l == r){
            return std::numeric_limits<int>::max();
        }
        int k = std::bit_width<uint32_t>(r - l) - 1;
        int x = st[k][l];
        int y = st[k][r - (1 << k)];
        return (x < y ? x : y);
    }
    int prod(int l, int r) const {
        assert(l < r);
        r--;
        int x = l >> LG, y = r >> LG;
        if (x < y){
            int p1 = suf[l];
            int p2 = st_prod(x + 1, y);
            int p3 = pre[r];
            return (p1 < p2 ? (p1 < p3 ? p1 : p3) : (p2 < p3 ? p2 : p3));
        }
        int ret = a[l];
        for (int i = l + 1; i <= r; i++){
            if (ret > a[i]){
                ret = a[i];
            }
        }
        return ret;
    }
    int lca(int u, int v) const {
        if (u == v) return u;
        u = down[u], v = down[v];
        if (u > v) std::swap(u, v);
        return prod(u, v);
    }
    uint dist(int u, int v) const {
        int l = lca(u, v);
        return dep[u] + dep[v] - 2 * dep[l];
    }
};

#line 2 "/Users/noya2/Desktop/Noya2_library/data_structure/csr.hpp"

#line 4 "/Users/noya2/Desktop/Noya2_library/data_structure/csr.hpp"
#include<ranges>
#line 7 "/Users/noya2/Desktop/Noya2_library/data_structure/csr.hpp"

namespace noya2::internal {

template<class E>
struct csr {
    csr () {}
    csr (int _n) : n(_n) {}
    csr (int _n, int m) : n(_n){
        start.reserve(m);
        elist.reserve(m);
    }
    // ACL style constructor (do not have to call build)
    csr (int _n, const std::vector<std::pair<int,E>> &idx_elem) : n(_n), start(_n + 2), elist(idx_elem.size()) {
        for (auto &[i, e] : idx_elem){
            start[i + 2]++;
        }
        for (int i = 1; i < n; i++){
            start[i + 2] += start[i + 1];
        }
        for (auto &[i, e] : idx_elem){
            elist[start[i + 1]++] = e;
        }
        prepared = true;
    }
    int add(int idx, E elem){
        int eid = start.size();
        start.emplace_back(idx);
        elist.emplace_back(elem);
        return eid;
    }
    void build(){
        if (prepared) return ;
        int m = start.size();
        std::vector<E> nelist(m);
        std::vector<int> nstart(n + 2, 0);
        for (int i = 0; i < m; i++){
            nstart[start[i] + 2]++;
        }
        for (int i = 1; i < n; i++){
            nstart[i + 2] += nstart[i + 1];
        }
        for (int i = 0; i < m; i++){
            nelist[nstart[start[i] + 1]++] = elist[i];
        }
        swap(elist,nelist);
        swap(start,nstart);
        prepared = true;
    }
    const auto operator[](int idx) const {
        return std::ranges::subrange(elist.begin()+start[idx],elist.begin()+start[idx+1]);
    }
    auto operator[](int idx){
        return std::ranges::subrange(elist.begin()+start[idx],elist.begin()+start[idx+1]);
    }
    const auto operator()(int idx, int l, int r) const {
        return std::ranges::subrange(elist.begin()+start[idx]+l,elist.begin()+start[idx]+r);
    }
    auto operator()(int idx, int l, int r){
        return std::ranges::subrange(elist.begin()+start[idx]+l,elist.begin()+start[idx]+r);
    }
    size_t size() const {
        return n;
    }
    int n;
    std::vector<int> start;
    std::vector<E> elist;
    bool prepared = false;
};

} // namespace noya2::internal
#line 102 "c.cpp"

struct simple_tree_for_yuki {
    internal::csr<int> g;
    simple_tree_for_yuki (int n) : g(n, (n - 1)*2) {}
    template<typename Stream>
    void input_edges(Stream &inputter){
        for (int i = 0; i < g.n - 1; i++){
            int u, v; inputter >> u >> v;
            u--, v--;
            g.add(u, v);
            g.add(v, u);
        }
        g.build();
    }
    const auto operator[](int v) const {
        return g[v];
    }
    auto operator[](int v){
        return g[v];
    }
    int size() const {
        return g.n;
    }
};

struct hld_tree_for_yuki {
    int n, root;
    std::vector<int> down, nxt, sub, tour;
    fast_lca fl;
    hld_tree_for_yuki (int _n) : n(_n), root(0), down(n), nxt(n), sub(n, 1), tour(n) {}
    template<typename Stream>
    void input_edges(Stream &inputter){
        for (int i = 1; i < n; i++){
            int u, v; inputter >> u >> v;
            u--, v--;
            down[u]++;
            down[v]++;
            nxt[u] ^= v;
            nxt[v] ^= u;
        }
        build_from_edges();
    }
    uint depth(int v) const {
        return fl.dep[down[v]];
    }
    uint dist(int u, int v) const {
        return fl.dist(down[u], down[v]);
    }
    int leader(int v) const {
        return nxt[v] < 0 ? v : nxt[v];
    }
    // down[v] : degree of v
    // nxt[v] : xor prod of neighbor of v
    void build_from_edges(){
        // use tour as queue
        int back = 0;
        for (int u = 0; u < n; u++){
            if (u != root && down[u] == 1){
                tour[back++] = u;
            }
        }
        for (int front = 0; front < n - 1; front++){
            int u = tour[front];
            down[u] = -1;
            int v = nxt[u]; // parent of v
            nxt[v] ^= u;
            if (--down[v] == 1 && v != root){
                tour[back++] = v;
            }
        }
        // check : now, tour is reverse of topological order

        tour.pop_back();

        // check : now, down[*] <= 1
        for (int u : tour){
            int v = nxt[u];
            // subtree size (initialized (1,1,...,1))
            sub[v] += sub[u];
            // heaviest subtree of its child
            if (down[v] < sub[u]){
                down[v] = sub[u];
            }
        }
        for (int u : tour){
            int v = nxt[u];
            // whether u is not the top of heavy path
            if (down[v] == sub[u]){
                sub[u] = ~sub[u];
                down[v] = ~down[v];
            }
        }

        // after appearing v as u (or v == root), 
        // down[v] is the visiting time of euler tour
        // nxt[v] is the lowest vertex of heavy path which contains v
        //   (if v itself, nxt[v] is ~(parent of v))
        // sub[v] + down[v] is the light child's starting time of euler tour
        // note : heavy child's visiting time of euler tour is (the time of its parent) + 1
        sub[root] = ~down[root] + 1;
        down[root] = 0;
        nxt[root] = -1;
        std::vector<int> par(n);
        for (int u : tour | std::views::reverse){
            int v = nxt[u];
            int nsub = ~down[u] + 1;
            // heavy child
            if (sub[u] < 0){
                down[u] = down[v] + 1;
                nxt[u] = (nxt[v] < 0 ? v : nxt[v]);
            }
            // light child
            else {
                down[u] = down[v] + sub[v];
                sub[v] += sub[u];
                nxt[u] = ~v;
            }
            sub[u] = nsub;
            par[down[u]] = down[v];
        }

        fl = fast_lca(par);

        // tour is inverse permutation of down
        tour.push_back(root);
        for (int u = 0; u < n; u++){
            tour[down[u]] = u;
        }
    }
};

#line 2 "/Users/noya2/Desktop/Noya2_library/tree/centroid_decomposition.hpp"

#line 4 "/Users/noya2/Desktop/Noya2_library/tree/centroid_decomposition.hpp"

namespace noya2 {

std::vector<int> centroid_decomposition(const auto &g){
    int n = g.size();
    if (n == 0){
        return {};
    }
    std::vector<int> sub(n), order;
    order.reserve(n);
    auto subtree = [&](auto sfs, int v, int f) -> void {
        sub[v] = 1;
        for (int u : g[v]){
            if (u == f) continue;
            sfs(sfs, u, v);
            sub[v] += sub[u];
        }
    };
    subtree(subtree,0,-1);
    auto fixed_root = [&](auto self, int root, int par, int cur_size) -> void {
        auto dfs = [&](auto sfs, int v, int f, int sz) -> int {
            int heavy = 0, child = -1;
            for (int u : g[v]){
                if (u == f) continue;
                if (heavy < sub[u]){
                    heavy = sub[u];
                    child = u;
                }
            }
            if (heavy > sz/2){
                int ret = sfs(sfs, child, v, sz);
                sub[v] -= ret;
                return ret;
            }
            else {
                order.emplace_back(v);
                for (int u : g[v]){
                    if (u == f) continue;
                    self(self, u, v, sub[u]);
                }
                int ret = sub[v];
                sub[v] = 0;
                return ret;
            }
        };
        while (cur_size > 0){
            cur_size -= dfs(dfs, root, par, cur_size);
        }
    };
    fixed_root(fixed_root, 0, -1, n);
    return order;
}

} // namespace noya2
#line 234 "c.cpp"

void solve(){
    using nachia::ncin, nachia::ncout;
    int n; ncin >> n;
    simple_tree_for_yuki a(n);
    hld_tree_for_yuki b(n);
    a.input_edges(ncin);
    b.input_edges(ncin);
    vector<int> spfensz(n);
    rep(v,n){
        int lv = b.leader(v);
        chmax(spfensz[lv], b.down[v] - b.down[lv] + 1);
    }
    vector<array<ull,2>> spfenfront(n,array<ull,2>{});
    vector<array<ull,4>> spfen(n,array<ull,4>{});
    ull rootdepsum = 0, rootdistsum = 0;
    auto apply_from_root = [&](int v, int dist, int sgn){
        ull x = 2 * sgn, y = 2 * dist * sgn;
        rootdepsum += x;
        rootdistsum += y;
        while (true){
            int lv = b.leader(v);
            int start = b.down[lv];
            int sz = spfensz[lv];
            int r = b.down[v] + 1 - start;
            int memor = r;
            r++;
            while (r <= sz){
                int id = r - 1 + start;
                spfen[id][0] += x * memor;
                spfen[id][1] += -x;
                spfen[id][2] += y * memor;
                spfen[id][3] += -y;
                r += r & -r;
            }
            spfenfront[start][0] += x;
            spfenfront[start][1] += y;
            if (lv == 0) break;
            v = ~b.nxt[lv];
        }
    };
    auto prod_from_root = [&](int v, int dist){
        ull depsum = -rootdepsum, distsum = -rootdistsum;
        while (true){
            int lv = b.leader(v);
            int start = b.down[lv];
            int r = b.down[v] + 1 - start;
            int memor = r;
            array<ull,4> prod = {};
            while (r > 0){
                int id = r - 1 + start;
                rep(i,4){
                    prod[i] += spfen[id][i];
                }
                r -= r & -r;
            }
            depsum += prod[0] + (prod[1] + spfenfront[start][0]) * memor;
            distsum += prod[2] + (prod[3] + spfenfront[start][1]) * memor;
            if (lv == 0) break;
            v = ~b.nxt[lv];
        }
        return depsum * dist + distsum;
    };
    vector<bool> done(n,false);
    ull ans = 0;
    for (int ctr : centroid_decomposition(a)){
        done[ctr] = true;
        vector<pii> vds = {{ctr,0}};
        vector<int> start = {0,1};
        auto dfs = [&](auto sfs, int v, int f, int dist) -> void {
            vds.emplace_back(v,dist);
            for (int u : a[v]){
                if (done[u]) continue;
                if (u == f) continue;
                sfs(sfs,u,v,dist+1);
            }
        };
        for (int v : a[ctr]){
            if (done[v]) continue;
            dfs(dfs,v,ctr,1);
            start.emplace_back(vds.size());
        }
        if (vds.size() < 100){
            int csz = start.size() - 2;
            rep(i,csz){
                rep(j,i){
                    repp(ii,start[i+1],start[i+2]){
                        repp(jj,start[j+1],start[j+2]){
                            auto [u, ud] = vds[ii];
                            auto [v, vd] = vds[jj];
                            ans += (ud + vd) * b.dist(u,v);
                        }
                    }
                }
                repp(ii,start[i+1],start[i+2]){
                    auto [v, vd] = vds[ii];
                    ans += vd * b.dist(ctr,v);
                }
            }
            continue;
        }
        // numof u, dist[u], dep[u], dist[u]*dep[u]
        ull cnt = 0, distsum = 0, depsum = 0, prdsum = 0;
        int csz = start.size() - 2;
        // v : ctr
        [&]{
            // dist[u] * dep[u]
            prdsum += 0;
            // dist[u] * dep[v]
            distsum += 0;
            // dist[v] * dep[u]
            depsum += b.depth(ctr);
            // dist[v] * dep[v]
            cnt += 1;
            // dist[u] * -2dep[lca(u,v)]
            // dist[v] * -2dep[lca(u,v)]
            apply_from_root(ctr, 0, -1);
        }();
        auto proc1 = [&](int v, int dist){
            // dist[u] * dep[u]
            ans += prdsum;
            // dist[u] * dep[v]
            ans += distsum * b.depth(v);
            // dist[v] * dep[u]
            ans += dist * depsum;
            // dist[v] * dep[v]
            ans += (ull)dist * b.depth(v) * cnt;
            // dist[u] * -2dep[lca(u,v)]
            // dist[v] * -2dep[lca(u,v)]
            ans += prod_from_root(v, dist);
        };
        auto proc2 = [&](int v, int dist){
            // dist[u] * dep[u]
            prdsum += (ull)dist * b.depth(v);
            // dist[u] * dep[v]
            distsum += dist;
            // dist[v] * dep[u]
            depsum += b.depth(v);
            // dist[v] * dep[v]
            cnt += 1;
            // dist[u] * -2dep[lca(u,v)]
            // dist[v] * -2dep[lca(u,v)]
            apply_from_root(v, dist, -1);
        };
        auto proc3 = [&](int v, int dist){
            // cancel of
            // dist[u] * -2dep[lca(u,v)]
            // dist[v] * -2dep[lca(u,v)]
            apply_from_root(v, dist, 1);
        };
        rep(i,csz){
            repp(j,start[i+1],start[i+2]){
                auto [v, dist] = vds[j];
                proc1(v,dist);
            }
            repp(j,start[i+1],start[i+2]){
                auto [v, dist] = vds[j];
                proc2(v,dist);
            }
        }
        rep(i,csz){
            repp(j,start[i+1],start[i+2]){
                auto [v, dist] = vds[j];
                proc3(v,dist);
            }
        }
        [&]{
            // cancel of
            // dist[u] * -2dep[lca(u,v)]
            // dist[v] * -2dep[lca(u,v)]
            apply_from_root(ctr, 0, 1);
        }();
    }
    ans *= 2;
    ncout << ans << '\n';
}

int main(){
    int t = 1; //in(t);
    while (t--) { solve(); }
}
0