結果
| 問題 | No.1333 Squared Sum |
| ユーザー |
 siro53
|
| 提出日時 | 2021-10-19 17:13:43 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 496 ms / 2,000 ms |
| コード長 | 8,837 bytes |
| コンパイル時間 | 2,634 ms |
| コンパイル使用メモリ | 212,440 KB |
| 最終ジャッジ日時 | 2025-01-25 01:54:17 |
|
ジャッジサーバーID （参考情報） |
judge2 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| other | AC * 44 |
ソースコード
#line 1 "main.cpp"#pragma region Macros#include <bits/stdc++.h>using namespace std;template <class T> inline bool chmax(T &a, T b) {if(a < b) {a = b;return 1;}return 0;}template <class T> inline bool chmin(T &a, T b) {if(a > b) {a = b;return 1;}return 0;}#ifdef DEBUGtemplate <class T, class U>ostream &operator<<(ostream &os, const pair<T, U> &p) {os << '(' << p.first << ',' << p.second << ')';return os;}template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {os << '{';for(int i = 0; i < (int)v.size(); i++) {if(i) { os << ','; }os << v[i];}os << '}';return os;}void debugg() { cerr << endl; }template <class T, class... Args>void debugg(const T &x, const Args &... args) {cerr << " " << x;debugg(args...);}#define debug(...) \cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__)#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl#else#define debug(...) (void(0))#define dump(x) (void(0))#endifstruct Setup {Setup() {cin.tie(0);ios::sync_with_stdio(false);cout << fixed << setprecision(15);}} __Setup;using ll = long long;#define OVERLOAD3(_1, _2, _3, name, ...) name#define ALL(v) (v).begin(), (v).end()#define RALL(v) (v).rbegin(), (v).rend()#define REP1(i, n) for(int i = 0; i < (n); i++)#define REP2(i, a, b) for(int i = (a); i < int(b); i++)#define REP(...) OVERLOAD3(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)#define UNIQUE(v) sort(ALL(v)), (v).erase(unique(ALL(v)), (v).end())const int INF = 1 << 30;const ll LLINF = 1LL << 60;constexpr int MOD = 1000000007;constexpr int MOD2 = 998244353;const int dx[4] = {1, 0, -1, 0};const int dy[4] = {0, 1, 0, -1};void Case(int i) { cout << "Case #" << i << ": "; }int popcount(int x) { return __builtin_popcount(x); }ll popcount(ll x) { return __builtin_popcountll(x); }#pragma endregion Macros#line 1 "/home/siro53/kyo-pro/compro_library/math/modint.hpp"template <int mod> struct ModInt {int x;ModInt() : x(0) {}ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}ModInt &operator+=(const ModInt &p) {if((x += p.x) >= mod)x -= mod;return *this;}ModInt &operator-=(const ModInt &p) {if((x += mod - p.x) >= mod)x -= mod;return *this;}ModInt &operator*=(const ModInt &p) {x = (int)(1LL * x * p.x % mod);return *this;}ModInt &operator/=(const ModInt &p) {*this *= p.inv();return *this;}ModInt operator-() const { return ModInt(-x); }ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }bool operator==(const ModInt &p) const { return x == p.x; }bool operator!=(const ModInt &p) const { return x != p.x; }ModInt inv() const {int a = x, b = mod, u = 1, v = 0, t;while(b > 0) {t = a / b;swap(a -= t * b, b);swap(u -= t * v, v);}return ModInt(u);}ModInt pow(int64_t n) const {ModInt ret(1), mul(x);while(n > 0) {if(n & 1)ret *= mul;mul *= mul;n >>= 1;}return ret;}friend ostream &operator<<(ostream &os, const ModInt &p) {return os << p.x;}friend istream &operator>>(istream &is, ModInt &a) {int64_t t;is >> t;a = ModInt<mod>(t);return (is);}static int get_mod() { return mod; }};#line 76 "main.cpp"using mint = ModInt<MOD>;#line 1 "/home/siro53/kyo-pro/compro_library/graph/re_rooting.hpp"template<class S, S (*op)(S, int), S (*merge)(S, S), S (*op2)(S, int), S (*e)()>class re_rooting {private:int N;vector<vector<int>> G;vector<vector<S>> dp;S dfs1(int u, int p) {S res = e();for(int i = 0; i < (int)G[u].size(); i++) {if(G[u][i] == p) continue;int v = G[u][i];dp[u][i] = dfs1(v, u);res = merge(res, op(dp[u][i], v));}return op2(res, u);}void dfs2(int u, int p, S from_par) {int sz = (int)G[u].size();for(int i = 0; i < sz; i++) {if(G[u][i] == p) {dp[u][i] = from_par;break;}}vector<S> rsum(sz + 1);rsum[sz] = e();for(int i = sz-1; i >= 0; i--) {rsum[i] = merge(rsum[i+1], op(dp[u][i], G[u][i]));}S lsum = e();for(int i = 0; i < sz; i++) {int v = G[u][i];if(v != p) {S val = merge(lsum, rsum[i+1]);dfs2(v, u, op2(val, u));}lsum = merge(lsum, op(dp[u][i], v));}}void build(int root) {for(int i = 0; i < N; i++) dp[i].resize(G[i].size());dfs1(root, -1);dfs2(root, -1, e());}public:re_rooting(int N): N(N), G(N), dp(N) {}re_rooting(const vector<vector<int>>& G): N(G.size()), G(G), dp(G.size()) {}void add_edge(int u, int v) {G[u].emplace_back(v);G[v].emplace_back(u);}vector<S> solve(int root = 0) {build(root);vector<S> ans(N);for(int u = 0; u < N; u++) {S res = e();for(int i = 0; i < (int)G[u].size(); i++) {res = merge(res, op(dp[u][i], G[u][i]));}ans[u] = op2(res, u);}return ans;}};template<class T>struct Edge {int from, to;T cost;Edge() = default;Edge(int from, int to, T cost): from(from), to(to), cost(cost) {}operator int() const { return to; }};template<class S, class Cost, S (*op)(S, Edge<Cost>), S (*merge)(S, S), S (*op2)(S, int), S (*e)()>class re_rooting_edge {private:int N;vector<vector<Edge<Cost>>> G;vector<vector<S>> dp;S dfs1(int u, int p) {S res = e();for(int i = 0; i < (int)G[u].size(); i++) {int v = G[u][i];if(v == p) continue;dp[u][i] = dfs1(v, u);res = merge(res, op(dp[u][i], G[u][i]));}return op2(res, u);}void dfs2(int u, int p, S from_par) {int sz = (int)G[u].size();for(int i = 0; i < sz; i++) {if(G[u][i] == p) {dp[u][i] = from_par;break;}}vector<S> rsum(sz + 1);rsum[sz] = e();for(int i = sz-1; i >= 0; i--) {rsum[i] = merge(rsum[i+1], op(dp[u][i], G[u][i]));}S lsum = e();for(int i = 0; i < sz; i++) {int v = G[u][i];if(v != p) {S val = merge(lsum, rsum[i+1]);dfs2(v, u, op2(val, u));}lsum = merge(lsum, op(dp[u][i], G[u][i]));}}void build(int root) {for(int i = 0; i < N; i++) dp[i].resize(G[i].size());dfs1(root, -1);dfs2(root, -1, e());}public:re_rooting_edge(int N): N(N), G(N), dp(N) {}re_rooting_edge(const vector<vector<Edge<Cost>>>& G): N(G.size()), G(G), dp(G.size()) {}void add_edge(int u, int v, Cost cost) {G[u].emplace_back(u, v, cost);G[v].emplace_back(v, u, cost);}vector<S> solve(int root = 0) {build(root);vector<S> ans(N);for(int u = 0; u < N; u++) {S res = e();for(int i = 0; i < (int)G[u].size(); i++) {res = merge(res, op(dp[u][i], G[u][i]));}ans[u] = op2(res, u);}return ans;}};#line 78 "main.cpp"using S = tuple<mint, mint, mint>;using Cost = mint;S op(S x, Edge<Cost> e) {auto [s2, d, sz] = x;return S(d*2*e.cost + s2 + e.cost*e.cost*(sz+1), d+e.cost*(sz+1), sz+1);}S merge(S x, S y) {auto [s2x, dx, szx] = x;auto [s2y, dy, szy] = y;return S(s2x + s2y, dx + dy, szx + szy);}S op2(S x, int id) {return x;}S e() { return {0, 0, 0}; }int main() {int N;cin >> N;re_rooting_edge<S, Cost, op, merge, op2, e> re(N);REP(i, N-1) {int u, v, w;cin >> u >> v >> w;u--; v--;re.add_edge(u, v, w);}auto dp = re.solve();mint ans = 0;REP(i, N) ans += get<0>(dp[i]);ans /= 2;cout << ans << endl;}