結果
| 問題 | No.1103 Directed Length Sum |
| ユーザー |
 maspy
|
| 提出日時 | 2022-05-09 19:20:55 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
AC
|
| 実行時間 | 633 ms / 3,000 ms |
| コード長 | 20,887 bytes |
| コンパイル時間 | 2,648 ms |
| コンパイル使用メモリ | 226,732 KB |
| 実行使用メモリ | 186,972 KB |
| 最終ジャッジ日時 | 2024-07-16 17:09:07 |
| 合計ジャッジ時間 | 9,845 ms |
|
ジャッジサーバーID （参考情報） |
judge4 / judge1 |
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テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | AC | 2 ms
5,248 KB |
| testcase_01 | AC | 2 ms
5,376 KB |
| testcase_02 | AC | 241 ms
186,972 KB |
| testcase_03 | AC | 117 ms
77,540 KB |
| testcase_04 | AC | 233 ms
46,016 KB |
| testcase_05 | AC | 633 ms
75,636 KB |
| testcase_06 | AC | 108 ms
30,632 KB |
| testcase_07 | AC | 20 ms
9,740 KB |
| testcase_08 | AC | 31 ms
13,800 KB |
| testcase_09 | AC | 13 ms
7,436 KB |
| testcase_10 | AC | 45 ms
16,992 KB |
| testcase_11 | AC | 249 ms
49,308 KB |
| testcase_12 | AC | 113 ms
31,172 KB |
| testcase_13 | AC | 47 ms
18,128 KB |
| testcase_14 | AC | 10 ms
6,944 KB |
| testcase_15 | AC | 76 ms
25,180 KB |
| testcase_16 | AC | 379 ms
55,852 KB |
| testcase_17 | AC | 517 ms
57,512 KB |
| testcase_18 | AC | 68 ms
17,736 KB |
| testcase_19 | AC | 453 ms
50,576 KB |
| testcase_20 | AC | 17 ms
8,284 KB |
| testcase_21 | AC | 26 ms
12,300 KB |
| testcase_22 | AC | 205 ms
41,504 KB |
| testcase_23 | AC | 86 ms
27,536 KB |
ソースコード
#line 1 "/home/maspy/compro/library/my_template.hpp"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pi = pair<ll, ll>;
using vi = vector<ll>;
using u32 = unsigned int;
using u64 = unsigned long long;
using i128 = __int128;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vector<vc<T>>;
template <class T>
using vvvc = vector<vvc<T>>;
template <class T>
using vvvvc = vector<vvvc<T>>;
template <class T>
using vvvvvc = vector<vvvvc<T>>;
template <class T>
using pq = priority_queue<T>;
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
#define vec(type, name, ...) vector<type> name(__VA_ARGS__)
#define vv(type, name, h, ...) \
vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define vvv(type, name, h, w, ...) \
vector<vector<vector<type>>> name( \
h, vector<vector<type>>(w, vector<type>(__VA_ARGS__)))
#define vvvv(type, name, a, b, c, ...) \
vector<vector<vector<vector<type>>>> name( \
a, vector<vector<vector<type>>>( \
b, vector<vector<type>>(c, vector<type>(__VA_ARGS__))))
#define FOR_(n) for (ll _ = 0; (_) < (ll)(n); ++(_))
#define FOR(i, n) for (ll i = 0; (i) < (ll)(n); ++(i))
#define FOR3(i, m, n) for (ll i = (m); (i) < (ll)(n); ++(i))
#define FOR_R(i, n) for (ll i = (ll)(n)-1; (i) >= 0; --(i))
#define FOR3_R(i, m, n) for (ll i = (ll)(n)-1; (i) >= (ll)(m); --(i))
#define FOR_subset(t, s) for (ll t = s; t >= 0; t = (t == 0 ? -1 : (t - 1) & s))
#define all(x) x.begin(), x.end()
#define len(x) ll(x.size())
#define elif else if
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
#define stoi stoll
template <typename T>
T SUM(vector<T> &A) {
T sum = T(0);
for (auto &&a: A) sum += a;
return sum;
}
#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define LB(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define UB(c, x) distance((c).begin(), upper_bound(all(c), (x)))
#define UNIQUE(x) sort(all(x)), x.erase(unique(all(x)), x.end())
int popcnt(int x) { return __builtin_popcount(x); }
int popcnt(u32 x) { return __builtin_popcount(x); }
int popcnt(ll x) { return __builtin_popcountll(x); }
int popcnt(u64 x) { return __builtin_popcountll(x); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 1, 2)
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(u32 x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int topbit(u64 x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 0, 2)
int lowbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(u32 x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
int lowbit(u64 x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
template <typename T, typename U>
T ceil(T x, U y) {
return (x > 0 ? (x + y - 1) / y : x / y);
}
template <typename T, typename U>
T floor(T x, U y) {
return (x > 0 ? x / y : (x - y + 1) / y);
}
template <typename T, typename U>
pair<T, T> divmod(T x, U y) {
T q = floor(x, y);
return {q, x - q * y};
}
ll binary_search(function<bool(ll)> check, ll ok, ll ng) {
assert(check(ok));
while (abs(ok - ng) > 1) {
auto x = (ng + ok) / 2;
if (check(x))
ok = x;
else
ng = x;
}
return ok;
}
template <class T, class S>
inline bool chmax(T &a, const S &b) {
return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
return (a > b ? a = b, 1 : 0);
}
vi s_to_vi(const string& S, char first_char) {
vi A(S.size());
FOR(i, S.size()) { A[i] = S[i] - first_char; }
return A;
}
template <typename T>
vector<T> cumsum(vector<T> &A, int off = 1) {
int N = A.size();
vector<T> B(N + 1);
FOR(i, N) { B[i + 1] = B[i] + A[i]; }
if (off == 0) B.erase(B.begin());
return B;
}
template <typename CNT, typename T>
vc<CNT> bincount(const vc<T> &A, int size) {
vc<CNT> C(size);
for (auto &&x: A) { ++C[x]; }
return C;
}
template <typename T>
vector<int> argsort(const vector<T> &A) {
// stable
vector<int> ids(A.size());
iota(all(ids), 0);
sort(all(ids),
[&](int i, int j) { return A[i] < A[j] || (A[i] == A[j] && i < j); });
return ids;
}
// A[I[0]], A[I[1]], ...
template <typename T>
vc<T> rearrange(const vc<T> &A, const vc<int> &I) {
int n = len(A);
assert(len(I) == n);
vc<T> B(n);
FOR(i, n) B[i] = A[I[i]];
return B;
}
#line 1 "/home/maspy/compro/library/other/io.hpp"
// based on yosupo's fastio
#include <unistd.h>
namespace detail {
template <typename T, decltype(&T::is_modint) = &T::is_modint>
std::true_type check_value(int);
template <typename T>
std::false_type check_value(long);
} // namespace detail
template <typename T>
struct is_modint : decltype(detail::check_value<T>(0)) {};
template <typename T>
using is_modint_t = enable_if_t<is_modint<T>::value>;
template <typename T>
using is_not_modint_t = enable_if_t<!is_modint<T>::value>;
struct Scanner {
FILE *fp;
char line[(1 << 15) + 1];
size_t st = 0, ed = 0;
void reread() {
memmove(line, line + st, ed - st);
ed -= st;
st = 0;
ed += fread(line + ed, 1, (1 << 15) - ed, fp);
line[ed] = '\0';
}
bool succ() {
while (true) {
if (st == ed) {
reread();
if (st == ed) return false;
}
while (st != ed && isspace(line[st])) st++;
if (st != ed) break;
}
if (ed - st <= 50) {
bool sep = false;
for (size_t i = st; i < ed; i++) {
if (isspace(line[i])) {
sep = true;
break;
}
}
if (!sep) reread();
}
return true;
}
template <class T, enable_if_t<is_same<T, string>::value, int> = 0>
bool read_single(T &ref) {
if (!succ()) return false;
while (true) {
size_t sz = 0;
while (st + sz < ed && !isspace(line[st + sz])) sz++;
ref.append(line + st, sz);
st += sz;
if (!sz || st != ed) break;
reread();
}
return true;
}
template <class T, enable_if_t<is_integral<T>::value, int> = 0>
bool read_single(T &ref) {
if (!succ()) return false;
bool neg = false;
if (line[st] == '-') {
neg = true;
st++;
}
ref = T(0);
while (isdigit(line[st])) { ref = 10 * ref + (line[st++] & 0xf); }
if (neg) ref = -ref;
return true;
}
template <class T, is_modint_t<T> * = nullptr>
bool read_single(T &ref) {
long long val = 0;
bool f = read_single(val);
ref = T(val);
return f;
}
bool read_single(double &ref) {
string s;
if (!read_single(s)) return false;
ref = std::stod(s);
return true;
}
bool read_single(char &ref) {
string s;
if (!read_single(s) || s.size() != 1) return false;
ref = s[0];
return true;
}
template <class T>
bool read_single(vector<T> &ref) {
for (auto &d: ref) {
if (!read_single(d)) return false;
}
return true;
}
template <class T, class U>
bool read_single(pair<T, U> &p) {
return (read_single(p.first) && read_single(p.second));
}
template <class A, class B, class C>
bool read_single(tuple<A, B, C> &p) {
return (read_single(get<0>(p)) && read_single(get<1>(p))
&& read_single(get<2>(p)));
}
template <class A, class B, class C, class D>
bool read_single(tuple<A, B, C, D> &p) {
return (read_single(get<0>(p)) && read_single(get<1>(p))
&& read_single(get<2>(p)) && read_single(get<3>(p)));
}
void read() {}
template <class H, class... T>
void read(H &h, T &... t) {
bool f = read_single(h);
assert(f);
read(t...);
}
Scanner(FILE *fp) : fp(fp) {}
};
struct Printer {
Printer(FILE *_fp) : fp(_fp) {}
~Printer() { flush(); }
static constexpr size_t SIZE = 1 << 15;
FILE *fp;
char line[SIZE], small[50];
size_t pos = 0;
void flush() {
fwrite(line, 1, pos, fp);
pos = 0;
}
void write(const char &val) {
if (pos == SIZE) flush();
line[pos++] = val;
}
template <class T, enable_if_t<is_integral<T>::value, int> = 0>
void write(T val) {
if (pos > (1 << 15) - 50) flush();
if (val == 0) {
write('0');
return;
}
if (val < 0) {
write('-');
val = -val; // todo min
}
size_t len = 0;
while (val) {
small[len++] = char(0x30 | (val % 10));
val /= 10;
}
for (size_t i = 0; i < len; i++) { line[pos + i] = small[len - 1 - i]; }
pos += len;
}
void write(const string &s) {
for (char c: s) write(c);
}
void write(const char *s) {
size_t len = strlen(s);
for (size_t i = 0; i < len; i++) write(s[i]);
}
void write(const double &x) {
ostringstream oss;
oss << setprecision(15) << x;
string s = oss.str();
write(s);
}
void write(const long double &x) {
ostringstream oss;
oss << setprecision(15) << x;
string s = oss.str();
write(s);
}
template <class T, is_modint_t<T> * = nullptr>
void write(T &ref) {
write(ref.val);
}
template <class T>
void write(const vector<T> &val) {
auto n = val.size();
for (size_t i = 0; i < n; i++) {
if (i) write(' ');
write(val[i]);
}
}
template <class T, class U>
void write(const pair<T, U> &val) {
write(val.first);
write(' ');
write(val.second);
}
template <class A, class B, class C>
void write(const tuple<A, B, C> &val) {
auto &[a, b, c] = val;
write(a), write(' '), write(b), write(' '), write(c);
}
template <class A, class B, class C, class D>
void write(const tuple<A, B, C, D> &val) {
auto &[a, b, c, d] = val;
write(a), write(' '), write(b), write(' '), write(c), write(' '), write(d);
}
template <class A, class B, class C, class D, class E>
void write(const tuple<A, B, C, D, E> &val) {
auto &[a, b, c, d, e] = val;
write(a), write(' '), write(b), write(' '), write(c), write(' '), write(d), write(' '), write(e);
}
template <class A, class B, class C, class D, class E, class F>
void write(const tuple<A, B, C, D, E, F> &val) {
auto &[a, b, c, d, e, f] = val;
write(a), write(' '), write(b), write(' '), write(c), write(' '), write(d), write(' '), write(e), write(' '), write(f);
}
template <class T, size_t S>
void write(const array<T, S> &val) {
auto n = val.size();
for (size_t i = 0; i < n; i++) {
if (i) write(' ');
write(val[i]);
}
}
void write(i128 val) {
string s;
bool negative = 0;
if(val < 0){
negative = 1;
val = -val;
}
while (val) {
s += '0' + int(val % 10);
val /= 10;
}
if(negative) s += "-";
reverse(all(s));
if (len(s) == 0) s = "0";
write(s);
}
};
Scanner scanner = Scanner(stdin);
Printer printer = Printer(stdout);
void flush() { printer.flush(); }
void print() { printer.write('\n'); }
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
printer.write(head);
if (sizeof...(Tail)) printer.write(' ');
print(forward<Tail>(tail)...);
}
void read() {}
template <class Head, class... Tail>
void read(Head &head, Tail &... tail) {
scanner.read(head);
read(tail...);
}
#define INT(...) \
int __VA_ARGS__; \
read(__VA_ARGS__)
#define LL(...) \
ll __VA_ARGS__; \
read(__VA_ARGS__)
#define STR(...) \
string __VA_ARGS__; \
read(__VA_ARGS__)
#define CHAR(...) \
char __VA_ARGS__; \
read(__VA_ARGS__)
#define DBL(...) \
double __VA_ARGS__; \
read(__VA_ARGS__)
#define VEC(type, name, size) \
vector<type> name(size); \
read(name)
#define VV(type, name, h, w) \
vector<vector<type>> name(h, vector<type>(w)); \
read(name)
void YES(bool t = 1) { print(t ? "YES" : "NO"); }
void NO(bool t = 1) { YES(!t); }
void Yes(bool t = 1) { print(t ? "Yes" : "No"); }
void No(bool t = 1) { Yes(!t); }
void yes(bool t = 1) { print(t ? "yes" : "no"); }
void no(bool t = 1) { yes(!t); }
#line 2 "/home/maspy/compro/library/graph/base.hpp"
template <typename T>
struct Edge {
int frm, to;
T cost;
int id;
};
template <typename T = int, bool directed = false>
struct Graph {
int N, M;
using cost_type = T;
using edge_type = Edge<T>;
vector<edge_type> edges;
vector<int> indptr;
vector<edge_type> csr_edges;
bool prepared;
class OutgoingEdges {
public:
OutgoingEdges(const Graph* G, int l, int r) : G(G), l(l), r(r) {}
const edge_type* begin() const {
if (l == r) { return 0; }
return &G->csr_edges[l];
}
const edge_type* end() const {
if (l == r) { return 0; }
return &G->csr_edges[r];
}
private:
int l, r;
const Graph* G;
};
bool is_prepared() { return prepared; }
constexpr bool is_directed() { return directed; }
Graph() : N(0), M(0), prepared(0) {}
Graph(int N) : N(N), M(0), prepared(0) {}
void add(int frm, int to, T cost = 1, int i = -1) {
assert(!prepared && 0 <= frm && 0 <= to && to < N);
if (i == -1) i = M;
auto e = edge_type({frm, to, cost, i});
edges.eb(e);
++M;
}
// wt, off
void read_tree(bool wt = false, int off = 1) { read_graph(N - 1, wt, off); }
void read_graph(int M, bool wt = false, int off = 1) {
FOR_(M) {
INT(a, b);
a -= off, b -= off;
if (!wt) {
add(a, b);
} else {
T c;
read(c);
add(a, b, c);
}
}
build();
}
void read_parent(int off = 1) {
FOR3(v, 1, N) {
INT(p);
p -= off;
add(p, v);
}
build();
}
void build() {
assert(!prepared);
prepared = true;
indptr.assign(N + 1, 0);
for (auto&& e: edges) {
indptr[e.frm + 1]++;
if (!directed) indptr[e.to + 1]++;
}
FOR(v, N) indptr[v + 1] += indptr[v];
auto counter = indptr;
csr_edges.resize(indptr.back() + 1);
for (auto&& e: edges) {
csr_edges[counter[e.frm]++] = e;
if (!directed)
csr_edges[counter[e.to]++] = edge_type({e.to, e.frm, e.cost, e.id});
}
}
OutgoingEdges operator[](int v) const {
assert(prepared);
return {this, indptr[v], indptr[v + 1]};
}
void debug() {
print("Graph");
if (!prepared) {
print("frm to cost id");
for (auto&& e: edges) print(e.frm, e.to, e.cost, e.id);
} else {
print("indptr", indptr);
print("frm to cost id");
FOR(v, N) for (auto&& e: (*this)[v]) print(e.frm, e.to, e.cost, e.id);
}
}
};
#line 2 "/home/maspy/compro/library/graph/degree.hpp"
template <typename Graph>
vector<int> degree(Graph& G) {
vector<int> deg(G.N);
for(auto&& e : G.edges) deg[e.frm]++, deg[e.to]++;
return deg;
}
template <typename Graph>
pair<vector<int>, vector<int>> degree_inout(Graph& G) {
vector<int> indeg(G.N), outdeg(G.N);
for (auto&& e: G.edges) { indeg[e.to]++, outdeg[e.frm]++; }
return {indeg, outdeg};
}
#line 3 "/home/maspy/compro/library/graph/toposort.hpp"
// DAG じゃなかったら空配列
// 辞書順最小もできる：O(NlogN) → abc223
template <typename Graph>
vc<int> toposort(Graph& G, bool lex_min = false) {
assert(G.is_prepared());
assert(G.is_directed());
auto [indeg, outdeg] = degree_inout(G);
if (!lex_min) {
vc<int> V;
ll N = G.N;
FOR(v, N) if (indeg[v] == 0) V.eb(v);
ll p = 0;
while (p < len(V)) {
auto v = V[p++];
for (auto&& e: G[v]) {
if (--indeg[e.to] == 0) V.eb(e.to);
}
}
if (len(V) < N) { V.clear(); }
return V;
} else {
pqg<int> que;
vc<int> V;
ll N = G.N;
FOR(v, N) if (indeg[v] == 0) que.push(v);
while (len(que)) {
auto v = que.top();
que.pop();
V.eb(v);
for (auto&& e: G[v]) {
if (--indeg[e.to] == 0) que.push(e.to);
}
}
if (len(V) < N) { V.clear(); }
return V;
}
}
// https://codeforces.com/contest/798/problem/E
// toposort の候補をひとつ出力する。チェックはしない。
// 陽にグラフを作らず、何らかのデータ構造で未訪問の行き先を探す想定。
// set_used(v)：v を使用済に変更する
// find_unused(v)：v の行き先を探す。なければ -1 を返すこと。
template <typename F1, typename F2>
vc<int> toposort(int N, F1 set_used, F2 find_unused) {
vc<int> V;
vc<bool> done(N);
auto dfs = [&](auto self, ll v) -> void {
set_used(v);
done[v] = 1;
while (1) {
int to = find_unused(v);
if (to == -1) break;
self(self, to);
}
V.eb(v);
};
FOR(v, N) if (!done[v]) dfs(dfs, v);
return V;
}
#line 3 "/home/maspy/compro/library/graph/hld.hpp"
/*
HL分解。O(N) 時間構築。
LCA, LA などは O(logN) 時間。
木以外、非連結でも使えるようにした。dfs順序や親がとれる。
*/
template <typename Graph>
struct HLD {
Graph &G;
int N;
vector<int> LID, RID, head, V, parent, root;
vc<ll> depth;
vector<bool> in_tree;
HLD(Graph &G, int r = -1)
: G(G),
N(G.N),
LID(G.N),
RID(G.N),
head(G.N, r),
V(G.N),
parent(G.N, -1),
depth(G.N, -1),
root(G.N, -1),
in_tree(G.M, 0) {
assert(G.is_prepared());
int t1 = 0;
if (r != -1) {
dfs_sz(r, -1);
dfs_hld(r, t1);
} else {
FOR(r, N) if (parent[r] == -1) {
head[r] = r;
dfs_sz(r, -1);
dfs_hld(r, t1);
}
}
for (auto &&v: V) root[v] = (parent[v] == -1 ? v : root[parent[v]]);
}
void dfs_sz(int v, int p) {
auto &sz = RID;
parent[v] = p;
depth[v] = (p == -1 ? 0 : depth[p] + 1);
sz[v] = 1;
int l = G.indptr[v], r = G.indptr[v + 1];
auto &csr = G.csr_edges;
// 使う辺があれば先頭にする
FOR3_R(i, l, r - 1) {
if (depth[csr[i + 1].to] == -1) swap(csr[i], csr[i + 1]);
}
int hld_sz = 0;
for (int i = l; i < r; ++i) {
auto e = csr[i];
if (depth[e.to] != -1) continue;
in_tree[e.id] = 1;
dfs_sz(e.to, v);
sz[v] += sz[e.to];
if (chmax(hld_sz, sz[e.to]) && l < i) { swap(csr[l], csr[i]); }
}
}
void dfs_hld(int v, int ×) {
LID[v] = times++;
RID[v] += LID[v];
V[LID[v]] = v;
bool heavy = true;
for (auto &&e: G[v]) {
if (!in_tree[e.id] || depth[e.to] <= depth[v]) continue;
head[e.to] = (heavy ? head[v] : e.to);
heavy = false;
dfs_hld(e.to, times);
}
}
int e_to_v(int eid) {
auto e = G.edges[eid];
return (parent[e.frm] == e.to ? e.frm : e.to);
}
int ELID(int v) { return 2 * LID[v] - depth[v]; }
int ERID(int v) { return 2 * RID[v] - depth[v] - 1; }
/* k: 0-indexed */
int LA(int v, int k) {
while (1) {
int u = head[v];
if (LID[v] - k >= LID[u]) return V[LID[v] - k];
k -= LID[v] - LID[u] + 1;
v = parent[u];
}
}
int LCA(int u, int v) {
for (;; v = parent[head[v]]) {
if (LID[u] > LID[v]) swap(u, v);
if (head[u] == head[v]) return u;
}
}
int lca(int u, int v) { return LCA(u, v); }
int la(int u, int v) { return LA(u, v); }
int subtree_size(int v) { return RID[v] - LID[v]; }
int dist(int a, int b) {
int c = LCA(a, b);
return depth[a] + depth[b] - 2 * depth[c];
}
bool in_subtree(int a, int b) { return LID[b] <= LID[a] && LID[a] < RID[b]; }
int move(int a, int b) {
assert(a != b);
return (in_subtree(b, a) ? LA(b, depth[b] - depth[a] - 1) : parent[a]);
}
vc<int> collect_child(int v) {
vc<int> res;
for (auto &&e: G[v])
if (e.to != parent[v]) res.eb(e.to);
return res;
}
vc<pair<int, int>> get_path_decomposition(int u, int v, bool edge) {
// [始点, 終点] の"閉"区間列。
vc<pair<int, int>> up, down;
while (1) {
if (head[u] == head[v]) break;
if (LID[u] < LID[v]) {
down.eb(LID[head[v]], LID[v]);
v = parent[head[v]];
} else {
up.eb(LID[u], LID[head[u]]);
u = parent[head[u]];
}
}
if (LID[u] < LID[v]) down.eb(LID[u] + edge, LID[v]);
elif (LID[v] + edge <= LID[u]) up.eb(LID[u], LID[v] + edge);
reverse(all(down));
up.insert(up.end(), all(down));
return up;
}
void debug() {
print("V", V);
print("LID", LID);
print("RID", RID);
print("parent", parent);
print("depth", depth);
print("head", head);
print("in_tree(edge)", in_tree);
print("root", root);
}
};
#line 5 "main.cpp"
void solve() {
LL(N);
Graph<int, 1> G(N);
G.read_tree();
auto V = toposort(G);
auto root = V[0];
HLD hld(G, root);
i128 ANS = 0;
FOR(v, N) {
ANS += hld.depth[v] * hld.subtree_size(v);
// print(v, hld.depth[v], hld.subtree_size(v));
}
print(ANS % 1000000007);
}
signed main() {
cin.tie(nullptr);
ios::sync_with_stdio(false);
cout << setprecision(15);
ll T = 1;
// LL(T);
FOR(_, T) solve();
return 0;
}