#517960 (C++14) No.1126 SUM

• 問題: No.1126 SUM
• ユーザー: ok
• 提出日時: 2020-07-24 22:25:20
• 言語: C++14 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 4 ms / 1,000 ms
• コード長: 1,806 bytes
• コンパイル時間: 1,003 ms
• コンパイル使用メモリ: 83,624 KB
• 実行使用メモリ: 6,944 KB
• 最終ジャッジ日時: 2024-06-25 21:52:36
• 合計ジャッジ時間: 1,921 ms
• ジャッジサーバーID （参考情報）: judge5 / judge4

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	4 ms; 6,812 KB
testcase_01	AC	4 ms; 6,940 KB
testcase_02	AC	3 ms; 6,940 KB
testcase_03	AC	3 ms; 6,940 KB
testcase_04	AC	4 ms; 6,944 KB
testcase_05	AC	3 ms; 6,940 KB
testcase_06	AC	3 ms; 6,940 KB
testcase_07	AC	4 ms; 6,944 KB
testcase_08	AC	3 ms; 6,944 KB
testcase_09	AC	4 ms; 6,940 KB
testcase_10	AC	4 ms; 6,940 KB
testcase_11	AC	4 ms; 6,940 KB
testcase_12	AC	4 ms; 6,944 KB
testcase_13	AC	3 ms; 6,940 KB
testcase_14	AC	3 ms; 6,940 KB
testcase_15	AC	4 ms; 6,940 KB
testcase_16	AC	4 ms; 6,940 KB
testcase_17	AC	3 ms; 6,940 KB
testcase_18	AC	3 ms; 6,940 KB
testcase_19	AC	4 ms; 6,940 KB
testcase_20	AC	3 ms; 6,944 KB
testcase_21	AC	4 ms; 6,944 KB
testcase_22	AC	3 ms; 6,940 KB
testcase_23	AC	4 ms; 6,940 KB
testcase_24	AC	4 ms; 6,944 KB
testcase_25	AC	4 ms; 6,944 KB

ソースコード

#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<utility>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1'000'000'007; 

struct fast_io {
	fast_io(){
		std::cin.tie(nullptr);
		std::ios::sync_with_stdio(false);
	};
} fio;


class binomial_coefficients {
	long long MAX_VAL;
	vector<long long> fac, mmi;

public:

	binomial_coefficients(){
	}
	
	binomial_coefficients(long long num){
		init(num);
	}
	
	~binomial_coefficients(){
		
	}
	
	void init(long long num){
		MAX_VAL = num+1; 
		fac.resize(MAX_VAL);
		mmi.resize(MAX_VAL);
		
		factorial_mod();
		modular_multiplicatibe_inverse();
	}
	
	void factorial_mod(){
		 fac[0] = 1;
		for(long long i = 1; i < MAX_VAL; fac[i] %= MOD, i++)
			fac[i] = fac[i - 1] * (i % MOD);
	}
	
	long long power(long long x, long long n){
		long long ans = 1;
		for(;n;n >>= 1, x *= x, ans %= MOD, x %= MOD)
			if(n&1)ans*=x;
		return ans % MOD;
	}
	
	void exgcd(long long a, long long b, long long &x, long long &y){
		if(b == 0){
			x = 1;
			y = 0;
			return ;
		}
		exgcd(b, a % b, y, x);
		y -= a / b * x;
	}
	
	void modular_multiplicatibe_inverse(){
		long long x, y;  
		exgcd(fac[MAX_VAL - 1], MOD, x, y);
		mmi[MAX_VAL-1] = (x%MOD + MOD) % MOD;
		// mmi[MAX_VAL-1] = power(fac[MAX_VAL-1], MOD-2);
		for(long long i = MAX_VAL - 2; i >= 0; mmi[i]%=MOD, i--)
			mmi[i] = mmi[i + 1] * ((i + 1) % MOD);
	}
	
	long long combination(long long n, long long r){
		return n < r ? 0 :fac[n] * (mmi[r] * mmi[n-r] % MOD) % MOD;
	}
};

signed main(){
	cout<<fixed<<setprecision(10);
	
	int N, M;
	int sum = 0;
	binomial_coefficients bf;
	
	cin>>N>>M;
	
	bf.init(M+2);

	cout<< bf.combination(M+1, N+1)<<endl;
	
	
	return 0;
}