modint.hpp

[詳解]

#pragma once
#include"../../kyopro_library/template.hpp"
 
/// @brief ModInt
template<ll MOD>
struct ModInt {
    ModInt(ll x=0){ value=(x>=0?x%MOD:MOD-(-x)%MOD); }
 
    ModInt operator-() const { return ModInt(-value); }
    ModInt operator+() const { return ModInt(*this); }
    ModInt& operator+=(const ModInt& other) {
        value+=other.value;
        if(value>=MOD) value-=MOD;
        return*this;
    }
    ModInt& operator-=(const ModInt& other) {
        value+=MOD-other.value;
        if(value>=MOD) value-=MOD;
        return*this;
    }
    ModInt& operator*=(const ModInt other) {
        value=value*other.value%MOD;
        return*this;
    }
    ModInt& operator/=(ModInt other) {
        (*this)*=other.inv();
        return*this;
    }
    ModInt operator+(const ModInt& other) const { return ModInt(*this)+=other; }
    ModInt operator-(const ModInt& other) const { return ModInt(*this)-=other; }
    ModInt operator*(const ModInt& other) const { return ModInt(*this)*=other; }
    ModInt operator/(const ModInt& other) const { return ModInt(*this)/=other; }
    bool operator==(const ModInt& other) const { return value==other.value; }
    bool operator!=(const ModInt& other) const { return value!=other.value; }
    friend ostream& operator<<(ostream& os, const ModInt& x) { return os<<x.value; }
    friend istream& operator>>(istream& is, ModInt& x) {
        ll v;
        is>>v;
        x=ModInt<MOD>(v);
        return is;
    }
 
    ModInt pow(ll x) const {
        ModInt ret(1),mul(value);
        while(x) {
            if(x&1) ret*=mul;
            mul*=mul;
            x>>=1;
        }
        return ret;
    }
    ModInt inv() const { return pow(MOD-2); }
    ll val() {return value; }
    static constexpr ll get_mod() { return MOD; }
 
private:
    ll value;
};
 
using Mod998=ModInt<998244353>;
using Mod107=ModInt<1000000007>;
 
#define VM vector<mint>
#define VVM vector<vector<mint>>