結果

問題 No.1075 木の上の山
ユーザー kimiyukikimiyuki
提出日時 2020-06-05 22:46:59
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
WA  
実行時間 -
コード長 5,199 bytes
コンパイル時間 2,763 ms
コンパイル使用メモリ 216,108 KB
実行使用メモリ 22,048 KB
最終ジャッジ日時 2024-05-09 22:28:18
合計ジャッジ時間 7,104 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge4
このコードへのチャレンジ
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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
10,624 KB
testcase_01 AC 2 ms
5,376 KB
testcase_02 WA -
testcase_03 WA -
testcase_04 WA -
testcase_05 WA -
testcase_06 WA -
testcase_07 WA -
testcase_08 WA -
testcase_09 WA -
testcase_10 WA -
testcase_11 WA -
testcase_12 WA -
testcase_13 WA -
testcase_14 WA -
testcase_15 WA -
testcase_16 WA -
testcase_17 AC 29 ms
15,616 KB
testcase_18 TLE -
testcase_19 WA -
testcase_20 TLE -
testcase_21 -- -
testcase_22 -- -
testcase_23 -- -
testcase_24 -- -
testcase_25 -- -
testcase_26 -- -
testcase_27 -- -
testcase_28 -- -
testcase_29 -- -
testcase_30 -- -
testcase_31 -- -
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 # 

#line 1 "main.cpp"
#include <bits/stdc++.h>
#line 2 "/home/user/GitHub/competitive-programming-library/utils/macros.hpp"
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++ (i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++ (i))
#define REP_R(i, n) for (int i = (int)(n) - 1; (i) >= 0; -- (i))
#define REP3R(i, m, n) for (int i = (int)(n) - 1; (i) >= (int)(m); -- (i))
#define ALL(x) std::begin(x), std::end(x)
#line 3 "/home/user/GitHub/competitive-programming-library/modulus/modpow.hpp"

inline int32_t modpow(uint_fast64_t x, uint64_t k, int32_t MOD) {
    assert (/* 0 <= x and */ x < (uint_fast64_t)MOD);
    uint_fast64_t y = 1;
    for (; k; k >>= 1) {
        if (k & 1) (y *= x) %= MOD;
        (x *= x) %= MOD;
    }
    assert (/* 0 <= y and */ y < (uint_fast64_t)MOD);
    return y;
}
#line 4 "/home/user/GitHub/competitive-programming-library/modulus/modinv.hpp"

inline int32_t modinv_nocheck(int32_t value, int32_t MOD) {
    assert (0 <= value and value < MOD);
    if (value == 0) return -1;
    int64_t a = value, b = MOD;
    int64_t x = 0, y = 1;
    for (int64_t u = 1, v = 0; a; ) {
        int64_t q = b / a;
        x -= q * u; std::swap(x, u);
        y -= q * v; std::swap(y, v);
        b -= q * a; std::swap(b, a);
    }
    if (not (value * x + MOD * y == b and b == 1)) return -1;
    if (x < 0) x += MOD;
    assert (0 <= x and x < MOD);
    return x;
}

inline int32_t modinv(int32_t x, int32_t MOD) {
    int32_t y = modinv_nocheck(x, MOD);
    assert (y != -1);
    return y;
}
#line 7 "/home/user/GitHub/competitive-programming-library/modulus/mint.hpp"


/**
 * @brief quotient ring / 剰余環 $\mathbb{Z}/n\mathbb{Z}$
 */
template <int32_t MOD>
struct mint {
    int32_t value;
    mint() : value() {}
    mint(int64_t value_) : value(value_ < 0 ? value_ % MOD + MOD : value_ >= MOD ? value_ % MOD : value_) {}
    mint(int32_t value_, std::nullptr_t) : value(value_) {}
    explicit operator bool() const { return value; }
    inline mint<MOD> operator + (mint<MOD> other) const { return mint<MOD>(*this) += other; }
    inline mint<MOD> operator - (mint<MOD> other) const { return mint<MOD>(*this) -= other; }
    inline mint<MOD> operator * (mint<MOD> other) const { return mint<MOD>(*this) *= other; }
    inline mint<MOD> & operator += (mint<MOD> other) { this->value += other.value; if (this->value >= MOD) this->value -= MOD; return *this; }
    inline mint<MOD> & operator -= (mint<MOD> other) { this->value -= other.value; if (this->value <    0) this->value += MOD; return *this; }
    inline mint<MOD> & operator *= (mint<MOD> other) { this->value = (uint_fast64_t)this->value * other.value % MOD; return *this; }
    inline mint<MOD> operator - () const { return mint<MOD>(this->value ? MOD - this->value : 0, nullptr); }
    inline mint<MOD> pow(uint64_t k) const { return mint<MOD>(modpow(value, k, MOD), nullptr); }
    inline mint<MOD> inv() const { return mint<MOD>(modinv(value, MOD), nullptr); }
    inline mint<MOD> operator /  (mint<MOD> other) const { return *this *  other.inv(); }
    inline mint<MOD> operator /= (mint<MOD> other)       { return *this *= other.inv(); }
    inline bool operator == (mint<MOD> other) const { return value == other.value; }
    inline bool operator != (mint<MOD> other) const { return value != other.value; }
};
template <int32_t MOD> mint<MOD> operator * (int64_t value, mint<MOD> n) { return mint<MOD>(value) * n; }
template <int32_t MOD> std::istream & operator >> (std::istream & in, mint<MOD> & n) { int64_t value; in >> value; n = value; return in; }
template <int32_t MOD> std::ostream & operator << (std::ostream & out, mint<MOD> n) { return out << n.value; }
#line 4 "main.cpp"
using namespace std;

constexpr int MOD = 1000000007;
mint<MOD> solve(int n, int k, const vector<vector<int> > & g) {
    map<pair<int, int>, vector<mint<MOD> > > memo;
    auto go = [&](auto && go, int x, int parent) -> vector<mint<MOD> > {
        auto key = make_pair(x, parent);
        if (memo.count(key)) return memo[key];

        vector<mint<MOD> > dp(k, 1);
        for (int y : g[x]) if (y != parent) {
            auto sub = go(go, y, x);
            mint<MOD> acc = 0;
            if (parent == -1 and y < x) {
                REP (i, k) {
                    dp[i] *= acc;
                    acc += sub[i];
                }
            } else {
                REP (i, k) {
                    acc += sub[i];
                    dp[i] *= acc;
                }
            }
        }
        return memo[key] = dp;
    };

    mint<MOD> ans = 0;
    REP (root, n) {
        auto dp = go(go, root, -1);
        ans += accumulate(ALL(dp), mint<MOD>());
    }
    return ans;
}

// generated by online-judge-template-generator v4.1.1 (https://github.com/kmyk/online-judge-template-generator)
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    constexpr char endl = '\n';
    int n; cin >> n;
    int k; cin >> k;
    vector<vector<int> > g(n);
    REP (i, n - 1) {
        int a, b; cin >> a >> b;
        -- a;
        -- b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    auto ans = solve(n, k, g);
    cout << ans << endl;
    return 0;
}
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