結果

問題 No.1333 Squared Sum
ユーザー satashunsatashun
提出日時 2021-01-08 22:00:40
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 161 ms / 2,000 ms
コード長 4,196 bytes
コンパイル時間 2,078 ms
コンパイル使用メモリ 206,916 KB
実行使用メモリ 35,336 KB
最終ジャッジ日時 2023-08-10 09:31:31
合計ジャッジ時間 9,716 ms
ジャッジサーバーID
(参考情報)
judge12 / judge14
このコードへのチャレンジ(β)

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
4,380 KB
testcase_01 AC 1 ms
4,376 KB
testcase_02 AC 2 ms
4,384 KB
testcase_03 AC 134 ms
17,396 KB
testcase_04 AC 138 ms
17,408 KB
testcase_05 AC 138 ms
17,312 KB
testcase_06 AC 146 ms
17,376 KB
testcase_07 AC 146 ms
17,324 KB
testcase_08 AC 148 ms
17,436 KB
testcase_09 AC 161 ms
17,416 KB
testcase_10 AC 137 ms
17,380 KB
testcase_11 AC 133 ms
17,500 KB
testcase_12 AC 143 ms
17,456 KB
testcase_13 AC 152 ms
35,336 KB
testcase_14 AC 159 ms
25,884 KB
testcase_15 AC 158 ms
32,716 KB
testcase_16 AC 2 ms
4,380 KB
testcase_17 AC 2 ms
4,376 KB
testcase_18 AC 2 ms
4,376 KB
testcase_19 AC 2 ms
4,380 KB
testcase_20 AC 1 ms
4,376 KB
testcase_21 AC 1 ms
4,380 KB
testcase_22 AC 2 ms
4,376 KB
testcase_23 AC 2 ms
4,380 KB
testcase_24 AC 1 ms
4,380 KB
testcase_25 AC 1 ms
4,380 KB
testcase_26 AC 150 ms
34,664 KB
testcase_27 AC 148 ms
26,592 KB
testcase_28 AC 151 ms
34,344 KB
testcase_29 AC 131 ms
35,332 KB
testcase_30 AC 47 ms
9,156 KB
testcase_31 AC 26 ms
6,440 KB
testcase_32 AC 69 ms
11,820 KB
testcase_33 AC 53 ms
9,868 KB
testcase_34 AC 105 ms
14,504 KB
testcase_35 AC 72 ms
11,628 KB
testcase_36 AC 41 ms
8,324 KB
testcase_37 AC 43 ms
8,528 KB
testcase_38 AC 48 ms
9,528 KB
testcase_39 AC 85 ms
12,888 KB
testcase_40 AC 105 ms
17,992 KB
testcase_41 AC 112 ms
18,076 KB
testcase_42 AC 112 ms
18,108 KB
testcase_43 AC 107 ms
18,020 KB
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 #

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using pii = pair<int, int>;
template <class T>
using V = vector<T>;
template <class T>
using VV = V<V<T>>;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define rep(i, n) rep2(i, 0, n)
#define rep2(i, m, n) for (int i = m; i < (n); i++)
#define per(i, b) per2(i, 0, b)
#define per2(i, a, b) for (int i = int(b) - 1; i >= int(a); i--)
#define ALL(c) (c).begin(), (c).end()
#define SZ(x) ((int)(x).size())

constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }

template <class T, class U>
void chmin(T& t, const U& u) {
    if (t > u) t = u;
}
template <class T, class U>
void chmax(T& t, const U& u) {
    if (t < u) t = u;
}

template <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 << "{";
    rep(i, v.size()) {
        if (i) os << ",";
        os << v[i];
    }
    os << "}";
    return os;
}

#ifdef LOCAL
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << H;
    debug_out(T...);
}
#define debug(...) \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif

template <unsigned int MOD>
struct ModInt {
    using uint = unsigned int;
    using ull = unsigned long long;
    using M = ModInt;

    uint v;

    ModInt(ll _v = 0) { set_norm(_v % MOD + MOD); }
    M& set_norm(uint _v) {  //[0, MOD * 2)->[0, MOD)
        v = (_v < MOD) ? _v : _v - MOD;
        return *this;
    }

    explicit operator bool() const { return v != 0; }
    M operator+(const M& a) const { return M().set_norm(v + a.v); }
    M operator-(const M& a) const { return M().set_norm(v + MOD - a.v); }
    M operator*(const M& a) const { return M().set_norm(ull(v) * a.v % MOD); }
    M operator/(const M& a) const { return *this * a.inv(); }
    M& operator+=(const M& a) { return *this = *this + a; }
    M& operator-=(const M& a) { return *this = *this - a; }
    M& operator*=(const M& a) { return *this = *this * a; }
    M& operator/=(const M& a) { return *this = *this / a; }
    M operator-() const { return M() - *this; }
    M& operator++(int) { return *this = *this + 1; }
    M& operator--(int) { return *this = *this - 1; }

    M pow(ll n) const {
        if (n < 0) return inv().pow(-n);
        M x = *this, res = 1;
        while (n) {
            if (n & 1) res *= x;
            x *= x;
            n >>= 1;
        }
        return res;
    }

    M inv() const {
        ll a = v, b = MOD, p = 1, q = 0, t;
        while (b != 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(p -= t * q, q);
        }
        return M(p);
    }

    bool operator==(const M& a) const { return v == a.v; }
    bool operator!=(const M& a) const { return v != a.v; }
    friend ostream& operator<<(ostream& os, const M& a) { return os << a.v; }
    static uint get_mod() { return MOD; }
};

using Mint = ModInt<1000000007>;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int N;
    cin >> N;

    VV<pii> g(N);
    rep(i, N - 1) {
        int a, b, w;
        cin >> a >> b >> w;
        --a, --b;
        g[a].eb(b, w);
        g[b].eb(a, w);
    }

    Mint ans;

    V<Mint> sum0(N), sum1(N), sum2(N);

    auto dfs = [&](auto&& f, int v, int p) -> void {
        sum0[v] = 1;
        for (auto& [to, w] : g[v]) {
            if (to != p) {
                f(f, to, v);
                sum2[to] += sum0[to] * w * w + sum1[to] * 2 * w;
                sum1[to] += sum0[to] * w;
                ans += sum2[v] * sum0[to] + sum2[to] * sum0[v] +
                       sum1[v] * sum1[to] * 2;

                sum2[v] += sum2[to];
                sum1[v] += sum1[to];
                sum0[v] += sum0[to];
            }
        }
    };

    dfs(dfs, 0, -1);

    cout << ans << endl;

    return 0;
}
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