結果
問題 | No.1207 グラフX |
ユーザー |
![]() |
提出日時 | 2020-08-30 15:08:36 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 295 ms / 2,000 ms |
コード長 | 5,849 bytes |
コンパイル時間 | 3,264 ms |
コンパイル使用メモリ | 212,256 KB |
最終ジャッジ日時 | 2025-01-13 22:30:26 |
ジャッジサーバーID (参考情報) |
judge4 / judge5 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 46 |
ソースコード
#include <bits/stdc++.h>using namespace std;#define REP(i,n) for(ll i=0;i<(ll)n;i++)#define dump(x) cerr << #x << " = " << (x) << endl;#define spa << " " <<#define fi first#define se second#define ALL(a) (a).begin(),(a).end()#define ALLR(a) (a).rbegin(),(a).rend()using ld = long double;using ll = long long;using ull = unsigned long long;using pii = pair<int, int>;using pll = pair<long, long>;using pdd = pair<ld, ld>;template<typename T> struct V : vector<T> { using vector<T>::vector; };V() -> V<ll>;V(size_t) -> V<ll>;template<typename T> V(size_t, T) -> V<T>;template<typename T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }template<typename... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){os << "(" << v.first << ", " << v.second << ")"; return os;}template<typename T> ostream& operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }template<class T> ostream& operator<<(ostream& os, const vector<vector<T>> &v){ for(auto &e : v){os << e << "\n";} return os;}struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }void fail() { cout << -1 << '\n'; exit(0); }inline int popcount(const int x) { return __builtin_popcount(x); }inline int popcount(const ll x) { return __builtin_popcountll(x); }template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++){cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<endl;}};template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];for(ll i=1;i<n;i++)cerr spa v[i];cerr<<endl;};const ll INF = (1ll<<62);// const ld EPS = 1e-10;// const ld PI = acos(-1.0);const ll mod = (int)1e9 + 7;//const ll mod = 998244353;template <std::uint_fast64_t Modulus> class modint {// long long から modint を作るときは必ず正の数にしてからコンストラクタに入れること!// そうしないとバグりますusing u64 = std::uint_fast64_t;public:u64 a;constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {}constexpr u64 &value() noexcept { return a; }constexpr const u64 &value() const noexcept { return a; }constexpr modint operator+(const modint rhs) const noexcept {return modint(*this) += rhs;}constexpr modint operator-(const modint rhs) const noexcept {return modint(*this) -= rhs;}constexpr modint operator*(const modint rhs) const noexcept {return modint(*this) *= rhs;}constexpr modint operator/(const modint rhs) const noexcept {return modint(*this) /= rhs;}constexpr modint &operator+=(const modint rhs) noexcept {a += rhs.a;if (a >= Modulus) {a -= Modulus;}return *this;}constexpr modint &operator-=(const modint rhs) noexcept {if (a < rhs.a) {a += Modulus;}a -= rhs.a;return *this;}constexpr modint &operator*=(const modint rhs) noexcept {a = a * rhs.a % Modulus;return *this;}constexpr modint &operator/=(modint rhs) noexcept {u64 exp = Modulus - 2;while (exp) {if (exp % 2) {*this *= rhs;}rhs *= rhs;exp /= 2;}return *this;}};using mint = modint<mod>;using vm = vector<mint>;using vvm = vector<vm>;ostream& operator << (ostream& os, const mint v){os << v.value(); return os;}template <class T, class U> constexpr T power(T x, U exp) {T ret = static_cast<T>(1);while (exp) {if (exp % static_cast<U>(2) == static_cast<U>(1))ret *= x;exp /= static_cast<U>(2);x *= x;}return ::std::move(ret);}// par[i] ·は,iがrootなら-(連結成分のサイズ)を,iがrootではないならばrootを返す// root(x) は必ずroot を返すstruct UnionFindSize {vector<int> par;UnionFindSize(int n) : par(n, -1) { }void init(int n) { par.assign(n, -1); }int root(int x) {if (par[x] < 0) return x;else return par[x] = root(par[x]);}bool issame(int x, int y) {return root(x) == root(y);}bool merge(int x, int y) {x = root(x); y = root(y);if (x == y) return false;if (par[x] > par[y]) swap(x, y); // merge techniquepar[x] += par[y];par[y] = x;return true;}int size(int x) {return -par[root(x)];}void print(){cout << "uf: ";for(int i=0;i<(int)par.size();i++) cout << root(i) << " ";cout << endl;}};using Graph = V<V<pll>>;int main(){ll N, M, X;cin >> N >> M >> X;V<ll> x(M), y(M), z(M);REP(i, M) cin >> x[i] >> y[i] >> z[i];REP(i, M) x[i]--, y[i]--;V<ll> ids(M);iota(ALL(ids), 0);sort(ALL(ids), [&](ll x, ll y){return z[x] < z[y];});UnionFindSize uf(N);Graph G(N);mint res = 0;for(auto idx: ids){if(uf.merge(x[idx], y[idx])){G[x[idx]].emplace_back(y[idx], z[idx]);G[y[idx]].emplace_back(x[idx], z[idx]);}}auto dfs = [&](auto self, ll now, ll par)->ll{ll sz = 1;for(auto tup: G[now]){ll next = tup.first;ll zz = tup.second;if(next == par) continue;ll tmp_sz = self(self, next, now);res += mint(tmp_sz) * (N-tmp_sz) * power(mint(X), zz);sz += tmp_sz;}return sz;};dfs(dfs, 0, -1);cout << res << endl;return 0;}