結果
| 問題 |
No.1333 Squared Sum
|
| コンテスト | |
| ユーザー |
minato
|
| 提出日時 | 2023-03-20 23:12:45 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 267 ms / 2,000 ms |
| コード長 | 18,993 bytes |
| コンパイル時間 | 2,382 ms |
| コンパイル使用メモリ | 215,536 KB |
| 最終ジャッジ日時 | 2025-02-11 15:41:32 |
|
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
(要ログイン)
| ファイルパターン | 結果 |
|---|---|
| other | AC * 44 |
ソースコード
#line 1 "library-cpp/other/template.hpp"
// clang-format off
#include <bits/stdc++.h>
using namespace std;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
using i128 = __int128_t;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
template <class T> using maxheap = priority_queue<T>;
template <class T> using minheap = priority_queue<T, vector<T>, greater<T>>;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vector<T>>;
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP0(n) for (auto minato = decay_t<decltype(n)>{}; minato < (n); ++minato)
#define REP1(i, n) for (auto i = decay_t<decltype(n)>{}; (i) < (n); (i)++)
#define REP2(i, l, r) for (auto i = (l); (i) < (r); (i)++)
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1, REP0)(__VA_ARGS__)
#define OVERLOAD_RREP(_1, _2, _3, name, ...) name
#define RREP1(i, n) for (auto i = (n) - 1; (i) >= decay_t<decltype(n)>{}; (i)--)
#define RREP2(i, l, r) for (auto i = (r) - 1; (i) >= (l); (i)--)
#define rrep(...) OVERLOAD_RREP(__VA_ARGS__, RREP2, RREP1)(__VA_ARGS__)
#define all(x) begin(x), end(x)
template <class Container> int SZ(const Container& v) { return int(v.size()); }
template <class T> void UNIQUE(vector<T>& v) { v.erase(unique(v.begin(), v.end()), v.end()); }
template <class T> T MAX(const vector<T>& v) { return *max_element(v.begin(), v.end()); }
template <class T> T MIN(const vector<T>& v) { return *min_element(v.begin(), v.end()); }
template <class T> T SUM(const vector<T>& v) { return accumulate(v.begin(), v.end(), T(0)); }
template <class T> T ABS(T x) { return max(x, -x); }
template <class T1, class T2> bool chmax(T1& a, T2 b) { if (a < b) { a = b; return true; } return false; }
template <class T1, class T2> bool chmin(T1& a, T2 b) { if (a > b) { a = b; return true; } return false; }
int topbit(ull x) { return x == 0 ? -1 : 63 - __builtin_clzll(x); }
int botbit(ull x) { return x == 0 ? 64 : __builtin_ctzll(x); }
int popcount(ull x) { return __builtin_popcountll(x); }
int kthbit(ull x, int k) { return (x >> k) & 1; }
constexpr long long TEN(int x) { return x == 0 ? 1 : TEN(x - 1) * 10; }
template <typename S> void rearrange(const vector<S>& id) { (void)id; }
template <typename S, typename T> void rearrange_exec(const vector<S>& id, vector<T>& v) { vector<T> w(v.size()); for (size_t i = 0; i < id.size(); i++) { w[i] = v[id[i]]; } v.swap(w); }
template <typename S, typename Head, typename... Tail> void rearrange(const vector<S>& id, Head& a, Tail& ...tail) { rearrange_exec(id, a); rearrange(id, tail...); }
istream& operator>>(istream& is, __int128_t& x) {
x = 0;
string s;
is >> s;
int n = int(s.size()), it = 0;
if (s[0] == '-') it++;
for (; it < n; it++) x = (x * 10 + s[it] - '0');
if (s[0] == '-') x = -x;
return is;
}
ostream& operator<<(ostream& os, __int128_t x) {
if (x == 0) return os << 0;
if (x < 0) os << '-', x = -x;
deque<int> deq;
while (x) deq.emplace_front(x % 10), x /= 10;
for (int e : deq) os << e;
return os;
}
template <class T> vector<T> &operator++(vector<T>& v) { for (auto& e : v) { e++; } return v;}
template <class T> vector<T> operator++(vector<T>& v, int) { auto res = v; for (auto& e : v) { e++; } return res; }
template <class T> vector<T> &operator--(vector<T>& v) { for (auto& e : v) { e--; } return v; }
template <class T> vector<T> operator--(vector<T>& v, int) { auto res = v; for (auto& e : v) { e--; } return res; }
template <class T1, class T2> pair<T1, T2> operator-(const pair<T1, T2>& x) { return pair<T1, T2>(-x.first, -x.second); }
template <class T1, class T2> pair<T1, T2> operator-(const pair<T1, T2>& x, const pair<T1, T2>& y) { return pair<T1, T2>(x.first - y.first, x.second - y.second); }
template <class T1, class T2> pair<T1, T2> operator+(const pair<T1, T2>& x, const pair<T1, T2>& y) { return pair<T1, T2>(x.first + y.first, x.second + y.second); }
template <class T1, class T2> pair<T1, T2> operator+=(pair<T1, T2>& l, const pair<T1, T2>& r) { return l = l + r; }
template <class T1, class T2> pair<T1, T2> operator-=(pair<T1, T2>& l, const pair<T1, T2>& r) { return l = l - r; }
constexpr char ln = '\n';
const string YESNO[2] = {"NO", "YES"};
const string YesNo[2] = {"No", "Yes"};
void YES(bool t = true) { cout << YESNO[t] << "\n"; }
void NO(bool t = 1) { YES(!t); }
void Yes(bool t = true) { cout << YesNo[t] << "\n"; }
void No(bool t = 1) { Yes(!t); }
template <class T> void drop(T x) { cout << x << "\n"; exit(0); }
#define INT(...) \
int __VA_ARGS__; \
IN(__VA_ARGS__)
#define LL(...) \
ll __VA_ARGS__; \
IN(__VA_ARGS__)
#define STR(...) \
string __VA_ARGS__; \
IN(__VA_ARGS__)
#define CHR(...) \
char __VA_ARGS__; \
IN(__VA_ARGS__)
#define LDB(...) \
long double __VA_ARGS__; \
IN(__VA_ARGS__)
#define VEC(type, name, size) \
vector<type> name(size); \
IN(name)
#define VEC2(type, name1, name2, size) \
vector<type> name1(size), name2(size); \
for (int i = 0; i < size; i++) IN(name1[i], name2[i])
#define VEC3(type, name1, name2, name3, size) \
vector<type> name1(size), name2(size), name3(size); \
for (int i = 0; i < size; i++) IN(name1[i], name2[i], name3[i])
#define VEC4(type, name1, name2, name3, name4, size) \
vector<type> name1(size), name2(size), name3(size), name4(size); \
for (int i = 0; i < size; i++) IN(name1[i], name2[i], name3[i], name4[i]);
#define VV(type, name, N, M) \
vector<vector<type>> name(N, vector<type>(M)); \
IN(name)
template <class T> void scan(T& a) { cin >> a; }
template <class T> void scan(vector<T>& a) { for (auto& i : a) scan(i); }
void IN() {}
template <class Head, class... Tail> void IN(Head& head, Tail&... tail) { scan(head); IN(tail...); }
void print() { cout << "\n"; }
template <class T> void print(const vector<T>& v) { for (auto it = v.begin(); it != v.end(); ++it) { if (it != v.begin()) { cout << " "; } cout << *it; } print(); }
template <class T, class... Args> void print(const T& x, const Args& ... args) { cout << x; if (sizeof...(Args)) cout << " "; print(args...); }
#ifdef MINATO_LOCAL
template <class T1, class T2> ostream& operator<<(ostream& os, pair<T1, T2> p) { return os << "(" << p.first << ", " << p.second << ")"; }
template <size_t N, class TUPLE> void debug_tuple(ostream& os, TUPLE _) { (void)os; (void)_; }
template <size_t N, class TUPLE, class T, class ...Args> void debug_tuple(ostream &os, TUPLE t) { os << (N == 0 ? "" : ", ") << get<N>(t); debug_tuple<N + 1, TUPLE, Args...>(os, t); }
template <class ...Args> ostream& operator<<(ostream& os, tuple<Args...> t) { os << "("; debug_tuple<0, tuple<Args...>, Args...>(os, t); return os << ")"; }
string debug_delim(int& i) { return i++ == 0 ? "" : ", "; }
#define debug_embrace(x) { int i = 0; os << "{"; { x } return os << "}"; }
template <class T> ostream& operator<<(ostream& os, vector<T> v) { debug_embrace( for (T e : v) { os << debug_delim(i) << e; } ) }
template <class T, size_t N> ostream& operator<<(ostream& os, array<T, N> a) { debug_embrace( for (T e : a) { os << debug_delim(i) << e; } ) }
template <class T, size_t N> enable_if_t<!is_same_v<char, remove_cv_t<T>>, ostream>& operator<<(ostream& os, T(&a)[N]) { debug_embrace( for (T e : a) { os << debug_delim(i) << e; } ) }
template <class Key> ostream& operator<<(ostream& os, set<Key> s) { debug_embrace( for (Key e : s) { os << debug_delim(i) << e; }) }
template <class Key, class T> ostream& operator<<(ostream& os, map<Key, T> mp) { debug_embrace( for (auto e : mp) { os << debug_delim(i) << e; }) }
template <class Key> ostream& operator<<(ostream& os, multiset<Key> s) { debug_embrace( for (Key e : s) { os << debug_delim(i) << e; }) }
template <class T> ostream& operator<<(ostream& os, queue<T> q) { debug_embrace( for (; !q.empty(); q.pop()) { os << debug_delim(i) << q.front(); } ) }
template <class T> ostream& operator<<(ostream& os, deque<T> q) { debug_embrace( for (T e : q) { os << debug_delim(i) << e; } ) }
template <class T> ostream& operator<<(ostream& os, priority_queue<T> q) { debug_embrace( for (; !q.empty(); q.pop()) { os << debug_delim(i) << q.top(); } ) }
template <class T> ostream& operator<<(ostream& os, priority_queue<T, vector<T>, greater<T>> q) { debug_embrace( for (; !q.empty(); q.pop()) { os << debug_delim(i) << q.top(); } ) }
void debug_out() { cerr << endl; }
template <class T, class... Args> void debug_out(const T& x, const Args& ... args) { cerr << " " << x; debug_out(args...); }
#define debug(...) cerr << __LINE__ << " : [" << #__VA_ARGS__ << "] =", debug_out(__VA_ARGS__)
#else
#define debug(...) (void(0))
#endif
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// clang-format on
#line 2 "library-cpp/tree/Rerooting.hpp"
/**
* @brief 全方位木 DP
* @param n int 頂点数
* @param op (EdgeValue a, EdgeValue b) -> EdgeValue : dp の値の演算
* @param vtoe (VertexValue a, auto(Edge) e) -> EdgeValue : 頂点の dp
* の値をから辺の dp の値を計算する
* @param etov (EdgeValue a, int v) -> VertexValue : 辺の dp の値から頂点の dp
* の値を計算する
* @param id EdgeValue 単位元
*/
template <class EdgeValue,
class VertexValue,
class Weight,
class F,
class G,
class H>
struct Rerooting {
struct Edge {
int from;
int to;
Weight weight;
Edge(int from, int to, const Weight& weight)
: from(from), to(to), weight(weight) {
}
};
int n;
vector<vector<Edge>> g;
vector<VertexValue> subdp, dp;
F op;
G vtoe;
H etov;
EdgeValue id;
Rerooting() {
}
Rerooting(int n,
const F& op,
const G& vtoe,
const H& etov,
const EdgeValue& id)
: n(n), g(n), subdp(n), dp(n), op(op), vtoe(vtoe), etov(etov), id(id) {
}
void add_edge(int u, int v, const Weight& weight = Weight()) {
g[u].emplace_back(u, v, weight);
g[v].emplace_back(v, u, weight);
}
void build() {
dfs_sub(0, -1);
dfs_all(0, -1, VertexValue());
return;
}
VertexValue operator[](int i) const {
return dp[i];
}
#ifdef MINATO_LOCAL
friend ostream& operator<<(ostream& os, const Rerooting& r) {
os << "\nsubdp = " << r.subdp;
os << "\ndp = " << r.dp;
return os;
}
#endif
private:
void dfs_sub(int v, int pv) {
EdgeValue merge_value = id;
for (const Edge& edge : g[v]) {
if (edge.to == pv) continue;
dfs_sub(edge.to, v);
merge_value = op(merge_value, vtoe(subdp[edge.to], edge));
}
subdp[v] = etov(merge_value, v);
return;
}
void dfs_all(int v, int pv, const VertexValue& top) {
dp[v] = calc_dp(v, pv, top);
vector<EdgeValue> prefix_sum = get_prefix_sum(v, pv, top);
EdgeValue merge_value = id;
for (int i = int(g[v].size()) - 1; i >= 0; i--) {
if (g[v][i].to != pv) {
dfs_all(g[v][i].to, v, etov(op(merge_value, prefix_sum[i]), v));
merge_value = op(merge_value, vtoe(subdp[g[v][i].to], g[v][i]));
} else {
merge_value = op(merge_value, vtoe(top, g[v][i]));
}
}
return;
}
VertexValue calc_dp(int v, int pv, const VertexValue& top) const {
EdgeValue merge_value = id;
for (const Edge& edge : g[v]) {
if (edge.to == pv) {
merge_value = op(merge_value, vtoe(top, edge));
} else {
merge_value = op(merge_value, vtoe(subdp[edge.to], edge));
}
}
return etov(merge_value, v);
}
vector<EdgeValue> get_prefix_sum(int v,
int pv,
const VertexValue& top) const {
vector<EdgeValue> prefix_sum(g[v].size(), id);
for (int i = 0; i < int(g[v].size()) - 1; i++) {
if (g[v][i].to == pv) {
prefix_sum[i + 1] = op(prefix_sum[i], vtoe(top, g[v][i]));
} else {
prefix_sum[i + 1] =
op(prefix_sum[i], vtoe(subdp[g[v][i].to], g[v][i]));
}
}
return prefix_sum;
}
};
#line 1 "library-cpp/mod/ModInt.hpp"
template <int m> struct ModInt {
public:
static constexpr int mod() {
return m;
}
static ModInt raw(int v) {
ModInt x;
x._v = v;
return x;
}
ModInt() : _v(0) {
}
ModInt(long long v) {
long long x = (long long)(v % (long long)(umod()));
if (x < 0) x += umod();
_v = (unsigned int)(x);
}
unsigned int val() const {
return _v;
}
ModInt& operator++() {
_v++;
if (_v == umod()) _v = 0;
return *this;
}
ModInt& operator--() {
if (_v == 0) _v = umod();
_v--;
return *this;
}
ModInt operator++(int) {
ModInt result = *this;
++*this;
return result;
}
ModInt operator--(int) {
ModInt result = *this;
--*this;
return result;
}
ModInt& operator+=(const ModInt& rhs) {
_v += rhs._v;
if (_v >= umod()) _v -= umod();
return *this;
}
ModInt& operator-=(const ModInt& rhs) {
_v -= rhs._v;
if (_v >= umod()) _v += umod();
return *this;
}
ModInt& operator*=(const ModInt& rhs) {
unsigned long long z = _v;
z *= rhs._v;
_v = (unsigned int)(z % umod());
return *this;
}
ModInt& operator^=(long long n) {
ModInt x = *this;
*this = 1;
if (n < 0) x = x.inv(), n = -n;
while (n) {
if (n & 1) *this *= x;
x *= x;
n >>= 1;
}
return *this;
}
ModInt& operator/=(const ModInt& rhs) {
return *this = *this * rhs.inv();
}
ModInt operator+() const {
return *this;
}
ModInt operator-() const {
return ModInt() - *this;
}
explicit operator bool() const {
return _v != 0;
}
ModInt pow(long long n) const {
ModInt r = *this;
r ^= n;
return r;
}
ModInt inv() const {
int a = _v, b = umod(), y = 1, z = 0, t;
for (;;) {
t = a / b;
a -= t * b;
if (a == 0) {
assert(b == 1 || b == -1);
return ModInt(b * z);
}
y -= t * z;
t = b / a;
b -= t * a;
if (b == 0) {
assert(a == 1 || a == -1);
return ModInt(a * y);
}
z -= t * y;
}
}
friend ModInt operator+(const ModInt& lhs, const ModInt& rhs) {
return ModInt(lhs) += rhs;
}
friend ModInt operator-(const ModInt& lhs, const ModInt& rhs) {
return ModInt(lhs) -= rhs;
}
friend ModInt operator*(const ModInt& lhs, const ModInt& rhs) {
return ModInt(lhs) *= rhs;
}
friend ModInt operator/(const ModInt& lhs, const ModInt& rhs) {
return ModInt(lhs) /= rhs;
}
friend ModInt operator^(const ModInt& lhs, long long rhs) {
return ModInt(lhs) ^= rhs;
}
friend bool operator==(const ModInt& lhs, const ModInt& rhs) {
return lhs._v == rhs._v;
}
friend bool operator!=(const ModInt& lhs, const ModInt& rhs) {
return lhs._v != rhs._v;
}
friend ModInt operator+(long long lhs, const ModInt& rhs) {
return (ModInt(lhs) += rhs);
}
friend ModInt operator-(long long lhs, const ModInt& rhs) {
return (ModInt(lhs) -= rhs);
}
friend ModInt operator*(long long lhs, const ModInt& rhs) {
return (ModInt(lhs) *= rhs);
}
friend ostream& operator<<(ostream& os, const ModInt& M) {
return os << M._v;
}
friend istream& operator>>(istream& is, ModInt& M) {
long long x;
is >> x;
M = x;
return is;
}
private:
unsigned int _v;
static constexpr unsigned int umod() {
return m;
}
};
#line 1 "library-cpp/mod/ModCombination.hpp"
template <class M> struct ModCombination {
public:
ModCombination() {
}
ModCombination(int n) : n_(n), fac_(n + 1), facinv_(n + 1) {
assert(1 <= n);
fac_[0] = 1;
for (int i = 1; i <= n; i++) fac_[i] = fac_[i - 1] * i;
facinv_[n] = M(1) / fac_[n];
for (int i = n; i >= 1; i--) facinv_[i - 1] = facinv_[i] * i;
}
M fac(int k) const {
assert(0 <= k and k <= n_);
return fac_[k];
}
M facinv(int k) const {
assert(0 <= k and k <= n_);
return facinv_[k];
}
M inv(int k) const {
assert(1 <= k and k <= n_);
return facinv_[k] * fac_[k - 1];
}
M P(int n, int k) const {
if (k < 0 or k > n) return M(0);
assert(n <= n_);
return fac_[n] * facinv_[n - k];
}
M C(int n, int k) const {
if (k < 0 or k > n) return M(0);
assert(n <= n_);
return fac_[n] * facinv_[n - k] * facinv_[k];
}
M H(int n, int k) const {
if (n == 0 and k == 0) return M(1);
return C(n + k - 1, n);
}
M catalan(int n) const {
if (n == 0) return M(1);
return C(2 * n, n) - C(2 * n, n - 1);
}
private:
int n_;
vector<M> fac_, facinv_;
};
#line 5 "A.cpp"
// using mint = ModInt<998244353>;
using mint = ModInt<1000000007>;
using Tu = tuple<mint, mint, mint>;
void solve() {
INT(N);
auto op = [](Tu a, Tu b) {
auto [a0, a1, a2] = a;
auto [b0, b1, b2] = b;
return Tu(a0 + b0, a1 + b1, a2 + b2);
};
auto etov = [](Tu a, auto e) {
auto [a0, a1, a2] = a;
return Tu(a0 + a1 * e.weight * 2 + e.weight * e.weight * a2,
a1 + e.weight * a2, a2);
};
auto vtoe = [](Tu a, int v) {
(void)v;
auto [a0, a1, a2] = a;
return Tu(a0, a1, a2 + 1);
};
const Tu e = Tu(0, 0, 0);
Rerooting<Tu, Tu, mint, decltype(op), decltype(etov), decltype(vtoe)> r(
N, op, etov, vtoe, e);
rep(N - 1) {
INT(a, b, c);
a--;
b--;
r.add_edge(a, b, c);
}
r.build();
mint ans = 0;
rep(i, N) {
ans += get<0>(r[i]);
}
ans /= 2;
print(ans);
}
int main() {
cin.tie(nullptr);
ios::sync_with_stdio(false);
cout << fixed << setprecision(20);
cerr << fixed << setprecision(7);
int T = 1;
// cin >> T;
for (int test_case = 1; test_case <= T; test_case++) {
// debug(test_case);
solve();
}
}
minato