#1102577 (C++17) No.109 N! mod M

• 問題: No.109 N! mod M
• ユーザー: GOTKAKO
• 提出日時: 2025-07-03 19:31:46
• 言語: C++17 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 99 ms / 5,000 ms
• コード長: 8,775 bytes
• コンパイル時間: 1,986 ms
• コンパイル使用メモリ: 198,280 KB
• 実行使用メモリ: 7,844 KB
• 最終ジャッジ日時: 2025-07-03 19:31:50
• 合計ジャッジ時間: 3,288 ms
• ジャッジサーバーID （参考情報）: judge1 / judge2

ファイルパターン	結果
other	AC * 9

ソースコード

#include <bits/stdc++.h>
using namespace std;

//入力が必ず-mod<a<modの時.
template<const int mod>
struct modint{ //mod変更が不可能.
    public:
    long long v = 0;
    static void setmod(int m){} //飾り.
    static constexpr long long getmod(){return mod;}
    modint(){v = 0;} modint(int a){v = a<0?a+mod:a;} modint(long long a){v = a<0?a+mod:a;}
    modint(unsigned int a){v = a;} modint(unsigned long long a){v = a;}
    long long val()const{return v;}
 
    modint &operator=(const modint &b) = default;
    modint operator+()const{return (*this);}
    modint operator-()const{return modint(0)-(*this);}
    modint operator+(const modint b)const{return modint(v)+=b;}
    modint operator-(const modint b)const{return modint(v)-=b;}
    modint operator*(const modint b)const{return modint(v)*=b;}
    modint operator/(const modint b)const{return modint(v)/=b;}
    modint operator+=(const modint b){
        v += b.v; if(v >= mod) v -= mod;
        return *this;
    }
    modint operator-=(const modint b){
        v -= b.v; if(v < 0) v += mod; 
        return *this;
    }   
    modint operator*=(const modint b){v = v*b.v%mod; return *this;}
    modint operator/=(modint b){ //b!=0 mod素数が必須.
        if(b == 0) assert(false);
        int left = mod-2;
        while(left){if(left&1) *this *= b; b *= b; left >>= 1;}
        return *this;
    }
    modint operator++(){*this += 1; return *this;}
    modint operator--(){*this -= 1; return *this;}
    modint operator++(int){*this += 1; return *this;}
    modint operator--(int){*this -= 1; return *this;}
    bool operator==(const modint b)const{return v == b.v;}
    bool operator!=(const modint b)const{return v != b.v;}
    bool operator>(const modint b)const{return v > b.v;}
    bool operator>=(const modint b)const{return v >= b.v;}
    bool operator<(const modint b)const{return v < b.v;}
    bool operator<=(const modint b)const{return v <= b.v;}
    modint pow(long long n)const{
        modint ret = 1,p = v;
        if(n < 0) p = p.inv(),n = -n;
        while(n){
            if(n&1) ret *= p;
            p *= p; n >>= 1;
        }
        return ret;
    }
    modint inv()const{return modint(1)/v;} //素数mod必須.
};
 
template<int idx> //modが入力で与えられる場合. 
struct dynamic_modint{ //mod変更が可能 最初にsetmod必須 idxで複数個所持が可能.
    private:
    static int mod;
    public:
    long long v = 0;
    static constexpr long long getmod(){return mod;}
    static void setmod(int m){
        assert(m > 0);
        mod = m;
    }
    dynamic_modint(){v = 0;}
    dynamic_modint(int a){v = a<0?a+mod:a;} dynamic_modint(long long a){v = a<0?a+mod:a;}
    dynamic_modint(unsigned int a){v = a;}
    dynamic_modint(unsigned long long a){v = a;}
    long long val()const{return v;}
 
    dynamic_modint &operator=(const dynamic_modint &b) = default;
    dynamic_modint operator+()const{return (*this);}
    dynamic_modint operator-()const{return dynamic_modint(0)-(*this);}
    dynamic_modint operator+(const dynamic_modint b)const{return dynamic_modint(v)+=b;}
    dynamic_modint operator-(const dynamic_modint b)const{return dynamic_modint(v)-=b;}
    dynamic_modint operator*(const dynamic_modint b)const{return dynamic_modint(v)*=b;}
    dynamic_modint operator/(const dynamic_modint b)const{return dynamic_modint(v)/=b;}
    dynamic_modint operator+=(const dynamic_modint b){
        v += b.v; if(v >= mod) v -= mod;
        return *this;
    }
    dynamic_modint operator-=(const dynamic_modint b){
        v -= b.v; if(v < 0) v += mod; 
        return *this;
    }   
    dynamic_modint operator*=(const dynamic_modint b){v = v*b.v%mod; return *this;}
    dynamic_modint operator/=(dynamic_modint b){ //b!=0 mod素数が必須.
        if(b == 0) assert(false);
        int left = mod-2;
        while(left){if(left&1) *this *= b; b *= b; left >>= 1;}
        return *this;
    }
    dynamic_modint operator++(){*this += 1; return *this;}
    dynamic_modint operator--(){*this -= 1; return *this;}
    dynamic_modint operator++(int){*this += 1; return *this;}
    dynamic_modint operator--(int){*this -= 1; return *this;}
    bool operator==(const dynamic_modint b)const{return v == b.v;}
    bool operator!=(const dynamic_modint b)const{return v != b.v;}
    bool operator>(const dynamic_modint b)const{return v > b.v;}
    bool operator>=(const dynamic_modint b)const{return v >= b.v;}
    bool operator<(const dynamic_modint b)const{return v < b.v;}
    bool operator<=(const dynamic_modint b)const{return v <= b.v;}
    dynamic_modint pow(long long n)const{
        dynamic_modint ret = 1,p = v;
        if(n < 0) p = p.inv(),n = -n;
        while(n){
            if(n&1) ret *= p;
            p *= p; n >>= 1;
        }
        return ret;
    }
    dynamic_modint inv()const{return dynamic_modint(1)/v;} //素数mod必須.
};
template<int idx> int dynamic_modint<idx>::mod=998244353;
using mint = dynamic_modint<0>;

template<int idx>
struct Montgomery{
    //2^62未満&奇数modのみ.
    //初めにsetmodする.
    using u64 = uint64_t;
    using u128 = __uint128_t;
 
    private:
    static u64 mod,N2,Rsq; //N*N2≡1(mod N);
    //Rsq = R^2modN; R=2^64.
    u64 v = 0;
    public:
    long long val()const{return reduce(v);}
    static constexpr u64 getmod(){return mod;}
    static void setmod(u64 m){
        assert(m<(1LL<<62)&&(m&1));
        mod = m; N2 = mod;
        for(int i=0; i<5; i++) N2 *= 2-N2*mod;
        Rsq = (-u128(mod))%mod;
    }
    //reduce = T*R^-1modNを求める.
    u64 reduce(const u128 &T)const{
        //T*R^-1≡(T+(T*(-N2))modR*N)/R 2N未満なので-N必要かだけで良い.
        u64 ret = (T+u128(((u64)T)*(-N2))*mod)>>64;
        if(ret >= mod) ret -= mod;
        return ret;
    }
    //初期値<mod. 初めにw*R modN...->reduce(R^2)でok.
    Montgomery(){v = 0;} Montgomery(long long w):v(reduce(u128(w)*Rsq)){}
 
    Montgomery& operator=(const Montgomery &b) = default;
    Montgomery operator-()const{return Montgomery()-Montgomery(*this);}
    Montgomery operator+(const Montgomery &b)const{return Montgomery(*this)+=b;}
    Montgomery operator-(const Montgomery &b)const{return Montgomery(*this)-=b;}
    Montgomery operator*(const Montgomery &b)const{return Montgomery(*this)*=b;}
    Montgomery operator/(const Montgomery &b)const{return Montgomery(*this)/=b;}
    Montgomery& operator+=(const Montgomery &b){
        v += b.v;
        if(v >= mod) v -= mod;
        return (*this);
    }
    Montgomery& operator-=(const Montgomery &b){
        v += mod-b.v;
        if(v >= mod) v -= mod;
        return (*this);
    }
    Montgomery& operator*=(const Montgomery &b){
        v = reduce(u128(v)*b.v);
        return (*this);
    }
    Montgomery& operator/=(const Montgomery &b){
        (*this) *= b.inv();
        return (*this);
    }
    Montgomery pow(u64 b)const{
        Montgomery ret = 1,p = (*this);
        if(b < 0) p = p.inv(),b = -b;
        while(b){
            if(b&1) ret *= p;
            p *= p; b >>= 1;
        }
        return ret;
    }
    Montgomery inv()const{return pow(mod-2);}
 
    bool operator!=(const Montgomery &b)const{return v!=b.v;}
    bool operator==(const Montgomery &b)const{return v==b.v;}
};
template<int idx> uint64_t Montgomery<idx>::mod;
template<int idx> uint64_t Montgomery<idx>::N2;
template<int idx> uint64_t Montgomery<idx>::Rsq;
using mont = Montgomery<0>;
 
bool MillerRabin(long long N,const vector<long long> &A){
    mont::setmod(N);
    long long s = __builtin_ctzll(N-1),d = N-1;
    d >>= s;
    for(auto &a : A){
        if(N <= a) break;
        mont x = mont(a).pow(d);
        if(x != 1){
            long long t;
            for(t=0; t<s; t++){
                if(x == N-1) break;
                x *= x;
            }
            if(t == s) return false;
        }
    }
    return true;
}
bool isprime(const long long N){
    if(N <= 1) return false;
    else if(N == 2) return true;
    else if(N%2 == 0) return false;
    else if(N < 4759123141LL) return MillerRabin(N,{2,7,61});
    else return MillerRabin(N, {2,325,9375,28178,450775,9780504,1795265022});
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int T; cin >> T;
    while(T--){
        int N,mod; cin >> N >> mod;
        if(N >= mod){cout << "0\n"; continue;}
        mint::setmod(mod);
        if(N < 200000){
            mint answer = 1%mod;
            for(int i=1; i<=N; i++) answer *= i;
            cout << answer.v << "\n";
        }
        else{
            if(isprime(mod) == false){cout << "0\n"; continue;}

            mint answer = -1,div = 1;
            for(int i=mod-1; i>N; i--) div *= i;
            answer /= div;
            cout << answer.v << "\n";
        }  
    }    
}