結果

問題 No.196 典型DP (1)
ユーザー satashunsatashun
提出日時 2023-05-16 17:19:18
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 50 ms / 2,000 ms
コード長 10,638 bytes
コンパイル時間 2,526 ms
コンパイル使用メモリ 214,640 KB
実行使用メモリ 24,960 KB
最終ジャッジ日時 2024-12-14 16:27:45
合計ジャッジ時間 4,441 ms
ジャッジサーバーID
(参考情報)
judge1 / judge5
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
6,820 KB
testcase_01 AC 2 ms
6,816 KB
testcase_02 AC 2 ms
6,820 KB
testcase_03 AC 2 ms
6,820 KB
testcase_04 AC 2 ms
6,816 KB
testcase_05 AC 2 ms
6,820 KB
testcase_06 AC 2 ms
6,820 KB
testcase_07 AC 2 ms
6,816 KB
testcase_08 AC 2 ms
6,816 KB
testcase_09 AC 2 ms
6,816 KB
testcase_10 AC 2 ms
6,820 KB
testcase_11 AC 2 ms
6,816 KB
testcase_12 AC 2 ms
6,820 KB
testcase_13 AC 2 ms
6,816 KB
testcase_14 AC 2 ms
6,816 KB
testcase_15 AC 2 ms
6,816 KB
testcase_16 AC 4 ms
6,816 KB
testcase_17 AC 6 ms
6,816 KB
testcase_18 AC 9 ms
6,824 KB
testcase_19 AC 10 ms
6,820 KB
testcase_20 AC 13 ms
6,824 KB
testcase_21 AC 13 ms
6,816 KB
testcase_22 AC 14 ms
6,820 KB
testcase_23 AC 28 ms
12,160 KB
testcase_24 AC 24 ms
9,216 KB
testcase_25 AC 22 ms
8,576 KB
testcase_26 AC 50 ms
24,960 KB
testcase_27 AC 50 ms
24,960 KB
testcase_28 AC 49 ms
24,960 KB
testcase_29 AC 49 ms
24,960 KB
testcase_30 AC 49 ms
24,832 KB
testcase_31 AC 21 ms
6,816 KB
testcase_32 AC 20 ms
6,816 KB
testcase_33 AC 21 ms
6,816 KB
testcase_34 AC 20 ms
6,820 KB
testcase_35 AC 22 ms
6,820 KB
testcase_36 AC 21 ms
6,820 KB
testcase_37 AC 13 ms
6,816 KB
testcase_38 AC 20 ms
6,816 KB
testcase_39 AC 18 ms
6,816 KB
testcase_40 AC 21 ms
6,820 KB
testcase_41 AC 2 ms
6,816 KB
testcase_42 AC 2 ms
6,816 KB
testcase_43 AC 2 ms
6,820 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 #

#pragma region satashun
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;

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

template <class T>
V<T> make_vec(size_t a) {
    return V<T>(a);
}

template <class T, class... Ts>
auto make_vec(size_t a, Ts... ts) {
    return V<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}

template <typename T, typename V>
void fill_vec(T& v, const V& val) {
    v = val;
}

template <typename T, typename V>
void fill_vec(vector<T>& vec, const V& val) {
    for (auto& v : vec) fill_vec(v, val);
}

#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 <typename T>
int arglb(const V<T>& v, const T& x) {
    return distance(v.begin(), lower_bound(ALL(v), x));
}

template <typename T>
int argub(const V<T>& v, const T& x) {
    return distance(v.begin(), upper_bound(ALL(v), x));
}

template <class T>
void mkuni(vector<T>& v) {
    sort(ALL(v));
    v.erase(unique(ALL(v)), end(v));
}

template <class T>
vector<int> sort_by(const vector<T>& v, bool increasing = true) {
    vector<int> res(v.size());
    iota(res.begin(), res.end(), 0);

    if (increasing) {
        stable_sort(res.begin(), res.end(),
                    [&](int i, int j) { return v[i] < v[j]; });
    } else {
        stable_sort(res.begin(), res.end(),
                    [&](int i, int j) { return v[i] > v[j]; });
    }
    return res;
}

template <class T, class U>
istream& operator>>(istream& is, pair<T, U>& p) {
    is >> p.first >> p.second;
    return is;
}

template <class T, class U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    os << "(" << p.first << "," << p.second << ")";
    return os;
}

template <class T>
istream& operator>>(istream& is, vector<T>& v) {
    for (auto& x : v) {
        is >> x;
    }
    return is;
}

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;
}

template <class T>
ostream& operator<<(ostream& os, const set<T>& ST) {
    os << "{";
    for (auto it = ST.begin(); it != ST.end(); ++it) {
        if (it != ST.begin()) os << ",";
        os << *it;
    }
    os << "}";
    return os;
}

template <class T>
ostream& operator<<(ostream& os, const multiset<T>& ST) {
    os << "{";
    for (auto it = ST.begin(); it != ST.end(); ++it) {
        if (it != ST.begin()) os << ",";
        os << *it;
    }
    os << "}";
    return os;
}

template <class T, class U>
ostream& operator<<(ostream& os, const map<T, U>& MP) {
    for (auto it = MP.begin(); it != MP.end(); ++it) {
        os << "(" << it->first << ": " << it->second << ")";
    }
    return os;
}

string to_string(__int128_t x) {
    if (x == 0) return "0";
    string result;
    if (x < 0) {
        result += "-";
        x *= -1;
    }
    string t;
    while (x) {
        t.push_back('0' + x % 10);
        x /= 10;
    }
    reverse(t.begin(), t.end());
    return result + t;
}

ostream& operator<<(ostream& o, __int128_t x) { return o << to_string(x); }

#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 <class T>
V<T>& operator+=(V<T>& vec, const T& v) {
    for (auto& x : vec) x += v;
    return vec;
}

template <class T>
V<T>& operator-=(V<T>& vec, const T& v) {
    for (auto& x : vec) x -= v;
    return vec;
}

// suc : 1 = newline, 2 = space
template <class T>
void print(T x, int suc = 1) {
    cout << x;
    if (suc == 1)
        cout << "\n";
    else if (suc == 2)
        cout << " ";
}

template <class T>
void print(const vector<T>& v, int suc = 1) {
    for (int i = 0; i < v.size(); ++i)
        print(v[i], i == int(v.size()) - 1 ? suc : 2);
}

template <class T>
void show(T x) {
    print(x, 1);
}

template <typename Head, typename... Tail>
void show(Head H, Tail... T) {
    print(H, 2);
    show(T...);
}

int topbit(int t) { return t == 0 ? -1 : 31 - __builtin_clz(t); }
int topbit(ll t) { return t == 0 ? -1 : 63 - __builtin_clzll(t); }
int botbit(int a) { return a == 0 ? 32 : __builtin_ctz(a); }
int botbit(ll a) { return a == 0 ? 64 : __builtin_ctzll(a); }
int popcount(int t) { return __builtin_popcount(t); }
int popcount(ll t) { return __builtin_popcountll(t); }
int bit_parity(int t) { return __builtin_parity(t); }
int bit_parity(ll t) { return __builtin_parityll(t); }

struct prepare_io {
    prepare_io() {
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(10);
    }
} prep_io;
#pragma endregion satashun

template <class T>
class Edge {
   public:
    int from, to, idx;
    T cost;

    Edge() = default;
    Edge(int from, int to, T cost = T(1), int idx = -1)
        : from(from), to(to), cost(cost), idx(idx) {}
    operator int() const { return to; }

    bool operator<(const Edge& e) const { return cost < e.cost; }
};

template <class T>
class Graph {
   public:
    using E = Edge<T>;
    vector<vector<E>> g;
    vector<E> edges;
    int es;

    Graph() {}
    Graph(int n) : g(n), edges(0), es(0){};

    int size() const { return g.size(); }

    virtual void add_directed_edge(int from, int to, T cost = 1) {
        g[from].emplace_back(from, to, cost, es++);
    }

    virtual void add_edge(int from, int to, T cost = 1) {
        g[from].emplace_back(from, to, cost, es);
        g[to].emplace_back(to, from, cost, es++);
    }

    inline vector<E>& operator[](const int& k) { return g[k]; }

    inline const vector<E>& operator[](const int& k) const { return g[k]; }

    void read(int M, int offset = -1, bool directed = false,
              bool weighted = false) {
        for (int i = 0; i < M; i++) {
            int a, b;
            cin >> a >> b;
            a += offset;
            b += offset;
            T c = T(1);
            if (weighted) cin >> c;
            edges.emplace_back(a, b, c, i);
            if (directed)
                add_directed_edge(a, b, c);
            else
                add_edge(a, b, c);
        }
    }
};

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; }
    explicit operator int() const { return v; }
    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);
    }

    friend ostream& operator<<(ostream& os, const M& a) { return os << a.v; }
    friend istream& operator>>(istream& in, M& x) {
        ll v_;
        in >> v_;
        x = M(v_);
        return in;
    }

    bool operator<(const M& r) const { return v < r.v; }
    bool operator>(const M& r) const { return v < *this; }
    bool operator<=(const M& r) const { return !(r < *this); }
    bool operator>=(const M& r) const { return !(*this < r); }
    bool operator==(const M& a) const { return v == a.v; }
    bool operator!=(const M& a) const { return v != a.v; }

    static uint get_mod() { return MOD; }
};

using Mint = ModInt<1000000007>;
// using Mint = ModInt<998244353>;

V<Mint> dp[2010][2];

void slv() {
    int N, K;
    cin >> N >> K;
    Graph<int> g(N);
    g.read(N - 1, 0, 0, 0);

    V<int> sz(N);

    auto rec = [&](auto&& f, int v, int p) -> void {
        dp[v][0].pb(1);
        dp[v][0].pb(0);
        dp[v][1].pb(0);
        dp[v][1].pb(1);
        sz[v] = 1;

        for (auto e : g[v]) {
            if (e.to == p) continue;
            f(f, e.to, v);

            while (SZ(dp[v][0]) <= sz[v] + sz[e.to]) dp[v][0].pb(0);
            while (SZ(dp[v][1]) <= sz[v] + sz[e.to]) dp[v][1].pb(0);

            per(i, sz[v] + 1) {
                per(j, sz[e.to] + 1) {
                    if (j) {
                        dp[v][0][i + j] +=
                            dp[v][0][i] * (dp[e.to][0][j] + dp[e.to][1][j]);
                        dp[v][1][i + j] += dp[v][1][i] * dp[e.to][1][j];
                    } else {
                        dp[v][0][i + j] =
                            dp[v][0][i] * (dp[e.to][0][j] + dp[e.to][1][j]);
                        dp[v][1][i + j] = dp[v][1][i] * dp[e.to][1][j];
                    }
                }
            }

            sz[v] += sz[e.to];
        }
    };

    rec(rec, 0, -1);

    Mint ans = dp[0][0][K] + dp[0][1][K];
    show(ans);
}

int main() {
    int cases = 1;
    // cin >> cases;
    rep(i, cases) slv();

    return 0;
}
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