結果
問題 | No.196 典型DP (1) |
ユーザー | Slephy |
提出日時 | 2023-08-30 15:43:35 |
言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
結果 |
AC
|
実行時間 | 13 ms / 2,000 ms |
コード長 | 10,030 bytes |
コンパイル時間 | 2,973 ms |
コンパイル使用メモリ | 214,988 KB |
実行使用メモリ | 6,948 KB |
最終ジャッジ日時 | 2024-06-10 15:37:00 |
合計ジャッジ時間 | 3,803 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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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
6,816 KB |
testcase_01 | AC | 2 ms
6,948 KB |
testcase_02 | AC | 2 ms
6,940 KB |
testcase_03 | AC | 2 ms
6,940 KB |
testcase_04 | AC | 2 ms
6,944 KB |
testcase_05 | AC | 2 ms
6,940 KB |
testcase_06 | AC | 2 ms
6,944 KB |
testcase_07 | AC | 2 ms
6,940 KB |
testcase_08 | AC | 2 ms
6,940 KB |
testcase_09 | AC | 2 ms
6,940 KB |
testcase_10 | AC | 2 ms
6,940 KB |
testcase_11 | AC | 2 ms
6,940 KB |
testcase_12 | AC | 2 ms
6,940 KB |
testcase_13 | AC | 2 ms
6,940 KB |
testcase_14 | AC | 2 ms
6,944 KB |
testcase_15 | AC | 2 ms
6,940 KB |
testcase_16 | AC | 3 ms
6,944 KB |
testcase_17 | AC | 4 ms
6,940 KB |
testcase_18 | AC | 5 ms
6,940 KB |
testcase_19 | AC | 5 ms
6,944 KB |
testcase_20 | AC | 7 ms
6,940 KB |
testcase_21 | AC | 7 ms
6,940 KB |
testcase_22 | AC | 7 ms
6,940 KB |
testcase_23 | AC | 7 ms
6,944 KB |
testcase_24 | AC | 7 ms
6,940 KB |
testcase_25 | AC | 7 ms
6,940 KB |
testcase_26 | AC | 6 ms
6,944 KB |
testcase_27 | AC | 6 ms
6,944 KB |
testcase_28 | AC | 5 ms
6,940 KB |
testcase_29 | AC | 5 ms
6,944 KB |
testcase_30 | AC | 5 ms
6,940 KB |
testcase_31 | AC | 13 ms
6,940 KB |
testcase_32 | AC | 13 ms
6,944 KB |
testcase_33 | AC | 13 ms
6,944 KB |
testcase_34 | AC | 13 ms
6,944 KB |
testcase_35 | AC | 13 ms
6,940 KB |
testcase_36 | AC | 13 ms
6,944 KB |
testcase_37 | AC | 8 ms
6,944 KB |
testcase_38 | AC | 13 ms
6,940 KB |
testcase_39 | AC | 11 ms
6,944 KB |
testcase_40 | AC | 13 ms
6,944 KB |
testcase_41 | AC | 2 ms
6,944 KB |
testcase_42 | AC | 2 ms
6,940 KB |
testcase_43 | AC | 2 ms
6,940 KB |
ソースコード
#include <bits/stdc++.h> using namespace std; using ll = long long; constexpr int INF = (int)1e9 + 1001010; constexpr ll llINF = (ll)4e18 + 22000020; const string endn = "\n"; template <class T> inline auto vector2(size_t i, size_t j, const T &init = T()) {return vector(i, vector<T>(j, init));} const string ELEM_SEPARATION = " ", VEC_SEPARATION = endn; template<class T> istream& operator >>(istream &i, vector<T> &A) {for(auto &I : A) {i >> I;} return i;} template<class T> ostream& operator <<(ostream &o, const vector<T> &A) {int i=A.size(); for(auto &I : A){o << I << (--i ? ELEM_SEPARATION : "");} return o;} template<class T> ostream& operator <<(ostream &o, const vector<vector<T>> &A) {int i=A.size(); for(auto &I : A){o << I << (--i ? VEC_SEPARATION : "");} return o;} template<class T> vector<T>& operator ++(vector<T> &A, int n) {for(auto &I : A) {I++;} return A;} template<class T> vector<T>& operator --(vector<T> &A, int n) {for(auto &I : A) {I--;} return A;} template<class T, class U> bool chmax(T &a, const U &b) {return ((a < b) ? (a = b, true) : false);} template<class T, class U> bool chmin(T &a, const U &b) {return ((a > b) ? (a = b, true) : false);} ll floor(ll a, ll b){if(b < 0) a = -a, b = -b; return a >= 0 ? a/b : (a+1)/b - 1;} ll ceil (ll a, ll b){if(b < 0) a = -a, b = -b; return a > 0 ? (a-1)/b + 1 : a/b;} ll bit(unsigned long long val, unsigned long long digit){return (val >> digit) & 1;} // ================================== ここまでテンプレ ================================== // modint namespace atcoder { namespace internal { constexpr long long safe_mod(long long x, long long m) { x %= m; if (x < 0) x += m; return x; } struct barrett { unsigned int _m; unsigned long long im; barrett(unsigned int m) : _m(m), im((unsigned long long)(-1) / m + 1) {} unsigned int umod() const { return _m; } unsigned int mul(unsigned int a, unsigned int b) const { unsigned long long z = a; z *= b; unsigned long long x = (unsigned long long)(((unsigned __int128)(z)*im) >> 64); unsigned int v = (unsigned int)(z - x * _m); if (_m <= v) v += _m; return v; } }; constexpr long long pow_mod_constexpr(long long x, long long n, int m) { if (m == 1) return 0; unsigned int _m = (unsigned int)(m); unsigned long long r = 1; unsigned long long y = safe_mod(x, m); while (n) { if (n & 1) r = (r * y) % _m; y = (y * y) % _m; n >>= 1; } return r; } constexpr bool is_prime_constexpr(int n) { if (n <= 1) return false; if (n == 2 || n == 7 || n == 61) return true; if (n % 2 == 0) return false; long long d = n - 1; while (d % 2 == 0) d /= 2; for (long long a : {2, 7, 61}) { long long t = d; long long y = pow_mod_constexpr(a, t, n); while (t != n - 1 && y != 1 && y != n - 1) { y = y * y % n; t <<= 1; } if (y != n - 1 && t % 2 == 0) { return false; } } return true; } template <int n> constexpr bool is_prime = is_prime_constexpr(n); constexpr std::pair<long long, long long> inv_gcd(long long a, long long b) { a = safe_mod(a, b); if (a == 0) return {b, 0}; long long s = b, t = a; long long m0 = 0, m1 = 1; while (t) { long long u = s / t; s -= t * u; m0 -= m1 * u; // |m1 * u| <= |m1| * s <= b auto tmp = s; s = t; t = tmp; tmp = m0; m0 = m1; m1 = tmp; } if (m0 < 0) m0 += b / s; return {s, m0}; } template <class T> using is_signed_int128 = typename std::conditional<std::is_same<T, __int128_t>::value || std::is_same<T, __int128>::value, std::true_type, std::false_type>::type; template <class T> using is_unsigned_int128 = typename std::conditional<std::is_same<T, __uint128_t>::value || std::is_same<T, unsigned __int128>::value, std::true_type, std::false_type>::type; template <class T> using make_unsigned_int128 = typename std::conditional<std::is_same<T, __int128_t>::value, __uint128_t, unsigned __int128>; template <class T> using is_signed_int = typename std::conditional<(is_integral<T>::value && std::is_signed<T>::value) || is_signed_int128<T>::value, std::true_type, std::false_type>::type; template <class T> using is_unsigned_int = typename std::conditional<(is_integral<T>::value && std::is_unsigned<T>::value) || is_unsigned_int128<T>::value, std::true_type, std::false_type>::type; template <class T> using to_unsigned = typename std::conditional< is_signed_int128<T>::value, make_unsigned_int128<T>, typename std::conditional<std::is_signed<T>::value, std::make_unsigned<T>, std::common_type<T>>::type>::type; template <class T> using is_signed_int_t = std::enable_if_t<is_signed_int<T>::value>; template <class T> using is_unsigned_int_t = std::enable_if_t<is_unsigned_int<T>::value>; } // namespace internal template <int m, std::enable_if_t<(1 <= m)>* = nullptr> struct static_modint { using mint = static_modint; public: static constexpr int mod() { return m; } static mint raw(int v) { mint x; x._v = v; return x; } static_modint() : _v(0) {} template <class T, internal::is_signed_int_t<T>* = nullptr> static_modint(T v) { long long x = (long long)(v % (long long)(umod())); if (x < 0) x += umod(); _v = (unsigned int)(x); } template <class T, internal::is_unsigned_int_t<T>* = nullptr> static_modint(T v) { _v = (unsigned int)(v % umod()); } static_modint(bool v) { _v = ((unsigned int)(v) % umod()); } unsigned int val() const { return _v; } mint& operator++() { _v++; if (_v == umod()) _v = 0; return *this; } mint& operator--() { if (_v == 0) _v = umod(); _v--; return *this; } mint operator++(int) { mint result = *this; ++*this; return result; } mint operator--(int) { mint result = *this; --*this; return result; } mint& operator+=(const mint& rhs) { _v += rhs._v; if (_v >= umod()) _v -= umod(); return *this; } mint& operator-=(const mint& rhs) { _v -= rhs._v; if (_v >= umod()) _v += umod(); return *this; } mint& operator*=(const mint& rhs) { unsigned long long z = _v; z *= rhs._v; _v = (unsigned int)(z % umod()); return *this; } mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); } mint operator+() const { return *this; } mint operator-() const { return mint() - *this; } mint pow(long long n) const { assert(0 <= n); mint x = *this, r = 1; while (n) { if (n & 1) r *= x; x *= x; n >>= 1; } return r; } mint inv() const { if (prime) { assert(_v); return pow(umod() - 2); } else { auto eg = internal::inv_gcd(_v, m); assert(eg.first == 1); return eg.second; } } friend mint operator+(const mint& lhs, const mint& rhs) { return mint(lhs) += rhs; } friend mint operator-(const mint& lhs, const mint& rhs) { return mint(lhs) -= rhs; } friend mint operator*(const mint& lhs, const mint& rhs) { return mint(lhs) *= rhs; } friend mint operator/(const mint& lhs, const mint& rhs) { return mint(lhs) /= rhs; } friend bool operator==(const mint& lhs, const mint& rhs) { return lhs._v == rhs._v; } friend bool operator!=(const mint& lhs, const mint& rhs) { return lhs._v != rhs._v; } friend istream &operator >> (istream &i, mint &a) {long long v; i >> v; a = v; return i;} friend ostream &operator << (ostream &os, const mint &a) { return os << a.val(); } private: unsigned int _v; static constexpr unsigned int umod() { return m; } static constexpr bool prime = internal::is_prime<m>; }; using modint998244353 = static_modint<998244353>; using modint1000000007 = static_modint<1000000007>; } // namespace atcoder using namespace atcoder; using mint = modint1000000007; int main(int argc, char *argv[]){ ios::sync_with_stdio(false); cin.tie(nullptr); ll n, k; cin >> n >> k; auto graph = vector2<int>(n, 0); for(int i = 0; i < n-1; i++){ int a, b; cin >> a >> b; graph[a].emplace_back(b); graph[b].emplace_back(a); } auto dfs = [&](auto &&dfs, int now, int par) -> vector<mint> { vector<vector<mint>> cdps; for(auto child : graph[now]){ if(child == par) continue; cdps.emplace_back(dfs(dfs, child, now)); } if(cdps.empty()){ return vector<mint>(2, 1); } vector<mint> cdp = cdps[0]; for(int cid = 1; cid < cdps.size(); cid++){ const auto &cdp2 = cdps[cid]; vector<mint> tmp(cdp.size() + cdp2.size() - 1, 0); for(int i = 0; i < cdp.size(); i++){ for(int j = 0; j < cdp2.size(); j++){ tmp[i+j] += cdp[i] * cdp2[j]; } } cdp = move(tmp); } cdp.emplace_back(1); return cdp; }; auto ans = dfs(dfs, 0, -1); cout << ans[k] << endl; return 0; }