結果

問題 No.665 Bernoulli Bernoulli
ユーザー snteasntea
提出日時 2018-05-11 12:27:18
言語 C++14
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 328 ms / 2,000 ms
コード長 6,086 bytes
コンパイル時間 1,591 ms
コンパイル使用メモリ 170,216 KB
実行使用メモリ 5,376 KB
最終ジャッジ日時 2024-06-28 03:56:06
合計ジャッジ時間 7,568 ms
ジャッジサーバーID
(参考情報)
judge2 / judge1
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
5,248 KB
testcase_01 AC 2 ms
5,376 KB
testcase_02 AC 326 ms
5,376 KB
testcase_03 AC 328 ms
5,376 KB
testcase_04 AC 310 ms
5,376 KB
testcase_05 AC 287 ms
5,376 KB
testcase_06 AC 284 ms
5,376 KB
testcase_07 AC 277 ms
5,376 KB
testcase_08 AC 299 ms
5,376 KB
testcase_09 AC 312 ms
5,376 KB
testcase_10 AC 272 ms
5,376 KB
testcase_11 AC 317 ms
5,376 KB
testcase_12 AC 311 ms
5,376 KB
testcase_13 AC 323 ms
5,376 KB
testcase_14 AC 324 ms
5,376 KB
testcase_15 AC 282 ms
5,376 KB
testcase_16 AC 296 ms
5,376 KB
testcase_17 AC 287 ms
5,376 KB
testcase_18 AC 278 ms
5,376 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 #

#ifdef LOCAL111
	#define _GLIBCXX_DEBUG
#else
	#define NDEBUG
#endif
#define _USE_MATH_DEFINES
#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <type_traits>
#include <typeindex>
#include <unordered_map>
#include <unordered_set>
#endif
const int INF = 1e9;
using namespace std;
template<typename T, typename U> ostream& operator<< (ostream& os, const pair<T,U>& p) { os << '(' << p.first << ' ' << p.second << ')'; return os; }

#define endl '\n'
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#ifdef LOCAL111
	#define DEBUG(x) cout<<#x<<": "<<(x)<<endl
	template<typename T> void dpite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
#else
	#define DEBUG(x) true
	template<typename T> void dpite(T a, T b){ return; }
#endif
#define F first
#define S second
#define SNP string::npos
#define WRC(hoge) cout << "Case #" << (hoge)+1 << ": "
template<typename T> void pite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}

typedef long long int LL;
typedef unsigned long long ULL;
typedef pair<int,int> P;

void ios_init(){
	//cout.setf(ios::fixed);
	//cout.precision(12);
#ifdef LOCAL111
	return;
#endif
	ios::sync_with_stdio(false); cin.tie(0);
}

template<long long MOD>
class ModInt {
public:
	const static long long mod = MOD;
	long long x;
	
	ModInt() {
		x = 0;
	}

	ModInt(long long x) {
		x %= mod;
		this->x = x < 0 ? x+mod : x;
	}

	int get() const {
		return (int)x;
	}

	ModInt &operator+=(ModInt that) {
		if((x += that.get()) >= mod) x -= mod;
		return *this;
	}

	ModInt &operator-=(ModInt that) {
		if((x += mod-that.get()) >= mod) x -= mod;
		return *this;
	}

	ModInt &operator*=(ModInt that) {
		x = x*that.get()%mod;
		return *this;
	}

	ModInt &operator/=(ModInt that) {
		return *this *= that.inverse();
	}

	ModInt operator+(ModInt that) const {
		return ModInt(*this) += that;
	}

	ModInt operator-(ModInt that) const {
		return ModInt(*this) -= that;
	}

	ModInt operator*(ModInt that) const {
		return ModInt(*this) *= that;
	}

	ModInt operator/(ModInt that) const {
		return ModInt(*this) /= that;
	}

	ModInt inverse() const {
		using std::swap;
		long long a = x, b = mod, u = 1, v = 0;
		while(b) {
			long long t = a/b;
			a -= t*b; swap(a,b);
			u -= t*v; swap(u,v);
		}
		return ModInt(u);
	}

	ModInt pow(int n) const{
		ModInt b = *this;
		ModInt res = 1;
		while(n != 0) {
			if(n&1){
				res *= b;
			}
			b *= b;
			n >>= 1;
		}
		return res;
	}

	bool operator==(ModInt that) const { return x == that.get(); }
	bool operator!=(ModInt that) const { return x != that.get(); }
	ModInt operator-() const { return x == 0 ? 0 : ModInt(mod-x); }
};

template<long long MOD> ostream& operator<< (ostream& os, const ModInt<MOD>& m) { os << m.get(); return os; }
template<long long MOD> istream& operator>> (istream& is, ModInt<MOD>& m){ long long n; is >> n; m = n; return is;}
typedef ModInt<1000000007> mint;



class ConvQuery {
	vector<mint> fac;
	vector<mint> facinv;

public:
	
	ConvQuery(int n) {
		fac = vector<mint>(n+1);
		facinv = vector<mint>(n+1);
		fac[0] = 1;
		facinv[0] = 1;
		for(int i = 0; i < n; ++i) {
			fac[i+1] = fac[i]*(i+1);
			facinv[i+1] = fac[i+1].inverse();
		}
	}

	mint operator()(int n, int m) {
		if(n >= 0 and 0 <= m and m <= n) return fac[n]*facinv[n-m]*facinv[m];
		else return 0;
	}
};


int main()
{
	ios_init();
	LL n, k;
    while(cin >> n >> k) {
        vector<mint> f(k+2);
        vector<mint> dp(k+2);
        f[1] = 1;
        dp[1] = mint(n) * mint(n+1) / 2;
        mint ka = mint(n) * mint(n+1) / 2;
        vector<mint> inv(k+1);
        FOR(i, 1, k+1) {
            inv[i] = mint(i).inverse();
        }
        FOR(i, 2, k+1) {
            DEBUG(i);
            mint pre = 0;
            ka *= n-i+1;
            ka /= i+1;
            DEBUG(ka);
            REP(j, i+2) {
                mint t = f[j];
                f[j] *= -(i-1);
                f[j] += pre;
                // f[j] /= i;
                f[j] *= inv[i];
                pre = t;
            }
            DEBUG(ka);
            dpite(ALL(f));
            dp[i] = ka;
            REP(j, i) {
                dp[i] -= dp[j] * f[j];
            }
            dp[i] /= f[i];
        }
        dpite(ALL(dp));
        cout << dp[k] << endl;
    }
	return 0;
}
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