結果
問題 |
No.1102 Remnants
|
ユーザー |
![]() |
提出日時 | 2020-07-03 22:29:47 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 50 ms / 2,000 ms |
コード長 | 4,095 bytes |
コンパイル時間 | 1,707 ms |
コンパイル使用メモリ | 198,072 KB |
最終ジャッジ日時 | 2025-01-11 14:54:23 |
ジャッジサーバーID (参考情報) |
judge2 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 25 |
ソースコード
#include <bits/stdc++.h> using namespace std; typedef unsigned long long ull; typedef long long ll; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef pair<double, double> pdd; typedef vector<ll> vll; typedef vector<vector<ll>> vvll; //typedef vector<vector<ll>> Graph; const ll mod = 1e9 + 7; //const ll mod = 998244353; #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 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; } template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){ os << "(" << v.first << ", " << v.second << ")"; return os; } template<class T> ostream& operator << (ostream& os, const vector<T> v){ for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << " ";} os << v[i];} return os; } template<class T> ostream& operator << (ostream& os, const vector<vector<T>> v){ for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os; } 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;}; string num2bit(ll num, ll len){ string bit = ""; REP(i, len){ bit += char('0'+(num>>i & 1)); } reverse(bit.begin(), bit.end()); return bit; } 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>; 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); } int main(){ cin.tie(0); ios::sync_with_stdio(false); ll N, K; cin >> N >> K; vector<ll> A(N); REP(i, N) cin >> A[i]; mint tmp = 0; REP(i, N) tmp += A[i]; tmp *= (K+1); // 二項係数 const int n_max = 500000; std::vector<mint> fact(n_max); fact[0] = 1; for (int i = 1; i < n_max; ++i) { fact[i] = fact[i - 1] * i; } const auto comb = [&fact](int n, int r) { if(n<r or n<0 or r<0) return mint(0); return fact[n] / fact[r] / fact[n - r]; }; mint res = 0; vector<mint> B(N, 0); B[0] = 1; REP(i, N-1){ B[i+1] = B[i] * mint(K+i+1) / mint(i+1); } REP(i, N){ res += B[i] * B[N-1-i] * A[i]; } cout << res.value() << endl; return 0; }