結果

問題 No.1573 Divisor Function
コンテスト
ユーザー milanis48663220
提出日時 2021-06-29 00:37:51
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 13 ms / 2,000 ms
コード長 2,992 bytes
コンパイル時間 935 ms
コンパイル使用メモリ 115,064 KB
最終ジャッジ日時 2025-01-22 14:49:26
ジャッジサーバーID
（参考情報） 		judge4 / judge2
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ファイルパターン 結果
sample AC * 3
other AC * 43
権限があれば一括ダウンロードができます
コンパイルメッセージ
In constructor ‘ModInt::ModInt(ll)’,
    inlined from ‘ModInt ModInt::operator/(ll)’ at main.cpp:44:24:
main.cpp:29:26: warning: ‘<unnamed>.ModInt::v’ may be used uninitialized [-Wmaybe-uninitialized]
   29 |         if(_v < 0) _v = (v%MOD)+MOD;
      |                          ^
main.cpp: In function ‘ModInt ModInt::operator/(ll)’:
main.cpp:44:32: note: ‘<anonymous>’ declared here
   44 |         return ModInt((ModInt(n).inv()*v).v%MOD);
      |                                ^
In constructor ‘ModInt::ModInt(ll)’,
    inlined from ‘mint cumsum(int)’ at main.cpp:113:12:
main.cpp:29:26: warning: ‘<unnamed>.ModInt::v’ may be used uninitialized [-Wmaybe-uninitialized]
   29 |         if(_v < 0) _v = (v%MOD)+MOD;
      |                          ^
main.cpp: In function ‘mint cumsum(int)’:
main.cpp:113:18: note: ‘<anonymous>’ declared here
  113 |     return mint(n)*mint(n+1)*mint(n+5)/6;
      |                  ^
In constructor ‘ModInt::ModInt(ll)’,
    inlined from ‘mint calc(int)’ at main.cpp:117:20:
main.cpp:29:26: warning: ‘<unnamed>.ModInt::v’ may be used uninitialized [-Wmaybe-uninitialized]
   29 |         if(_v < 0) _v = (v%MOD)+MOD;
      |                          ^
main.cpp: In function ‘mint calc(int)’:
main.cpp:117:26: note: ‘<anonymous>’ declared here
  117 |     return mint(x)+mint(x)*mint(x+1)/2;
      |                          ^
In constructor ‘ModInt::ModInt(ll)’,
    inlined from ‘mint calc(int)’ at main.cpp:117:12:
main.cpp:29:26: warning: ‘<unnamed>.ModInt::v’ may be used uninitialized [-Wmaybe-uninitialized]
   29 |         if(_v < 0) _v = (v%MOD)+MOD;
      |                          ^
main.cpp: In function ‘mint calc(int)’:
main.cpp:117:18: note: ‘<anonymous>’ declared here
  117 |     return mint(x)+mint(x)*mint(x+1)/2;
      |                  ^
In constructor ‘ModInt::ModInt(ll)’,
    inlined from ‘mint sect_sum(int, int)’ at main.cpp:121:12:
main.cpp:29:

ソースコード

diff # 

#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

const ll MOD = 998244353;

class ModInt{
    public:
    ll v;
    ModInt(ll _v = 0){
        if(_v < 0) _v = (v%MOD)+MOD;
        if(_v >= MOD) _v %= MOD;
        v = _v;
    }
    ModInt operator+(ll n){
        return ModInt((v+n)%MOD);
    }
    ModInt operator-(ll n){
        return ModInt((v-n+MOD)%MOD);
    }
    ModInt operator*(ll n){
        if(n >= MOD) n %= MOD;
        return ModInt((v*n)%MOD);
    }
    ModInt operator/(ll n){
        return ModInt((ModInt(n).inv()*v).v%MOD);
    }

    void operator+=(ll n){
        v = (v+n)%MOD;
    }
    void operator-=(ll n){
        v = (v-n+MOD)%MOD;
    }
    void operator*=(ll n){
        v = (v*n+MOD)%MOD;
    }
    
    
    ModInt operator+(ModInt n){
        return ModInt((v+n.v)%MOD);
    }
    ModInt operator-(ModInt n){
        return ModInt((v-n.v+MOD)%MOD);
    }
    ModInt operator*(ModInt n){
        return ModInt((v*n.v)%MOD);
    }
    ModInt operator/(ModInt n){
        return ModInt((n.inv()*v).v%MOD);
    }

    void operator+=(ModInt n){
        v = (v+n.v)%MOD;
    }
    void operator-=(ModInt n){
        v = (v-n.v+MOD)%MOD;
    }
    void operator*=(ModInt n){
        v = (v*n.v)%MOD;
    }

    void operator=(ModInt n){
        v = n.v;
    }
    bool operator==(ModInt n){
        return v == n.v;
    }
    bool operator!=(ModInt n){
        return v != n.v;
    }
    void operator=(ll n){
        v = n%MOD;
    }

    ModInt inv(){
        if(v == 1) return ModInt(1);
        else return ModInt(MOD-ModInt(MOD%v).inv().v*(MOD/v)%MOD);
    }
};

ostream& operator<<(ostream& os, const ModInt& m){
    os << m.v;
    return os;
}

istream & operator >> (istream &in,  ModInt &m){
    in >> m.v;
    return in;
}

using mint = ModInt;

mint cumsum(int n){
    return mint(n)*mint(n+1)*mint(n+5)/6;
}

mint calc(int x){ 
    return mint(x)+mint(x)*mint(x+1)/2;
}

mint sect_sum(int l, int r){
    return mint(l+r)*mint(r-l+1)/2;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n, m; cin >> n >> m;
    mint ans = 0;
    for(int i = 1; i*i <= n && i <= m; i++){
        ans += calc(n/i)*i;
        if(n/i == i) continue;
        int l = n/(i+1)+1;
        int r = n/i;
        if(l > m) continue;
        chmin(r, m);
        ans += calc(i)*sect_sum(l, r);
    }
    cout << ans << endl;
}
0