#818309 (C++17) No.2127 Mod, Sum, Sum, Mod

• 問題: No.2127 Mod, Sum, Sum, Mod
• ユーザー: pitP
• 提出日時: 2022-11-19 12:37:08
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 41 ms / 2,000 ms
• コード長: 2,023 bytes
• コンパイル時間: 4,460 ms
• コンパイル使用メモリ: 264,728 KB
• 実行使用メモリ: 4,348 KB
• 最終ジャッジ日時: 2023-10-20 17:48:59
• 合計ジャッジ時間: 5,687 ms
• ジャッジサーバーID （参考情報）: judge14 / judge15

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 4,348 KB
testcase_01	AC	2 ms; 4,348 KB
testcase_02	AC	41 ms; 4,348 KB
testcase_03	AC	2 ms; 4,348 KB
testcase_04	AC	2 ms; 4,348 KB
testcase_05	AC	2 ms; 4,348 KB
testcase_06	AC	2 ms; 4,348 KB
testcase_07	AC	2 ms; 4,348 KB
testcase_08	AC	2 ms; 4,348 KB
testcase_09	AC	2 ms; 4,348 KB
testcase_10	AC	2 ms; 4,348 KB
testcase_11	AC	2 ms; 4,348 KB
testcase_12	AC	2 ms; 4,348 KB
testcase_13	AC	2 ms; 4,348 KB
testcase_14	AC	2 ms; 4,348 KB
testcase_15	AC	2 ms; 4,348 KB
testcase_16	AC	2 ms; 4,348 KB
testcase_17	AC	2 ms; 4,348 KB
testcase_18	AC	2 ms; 4,348 KB
testcase_19	AC	2 ms; 4,348 KB
testcase_20	AC	2 ms; 4,348 KB
testcase_21	AC	2 ms; 4,348 KB
testcase_22	AC	41 ms; 4,348 KB
testcase_23	AC	41 ms; 4,348 KB
testcase_24	AC	2 ms; 4,348 KB
testcase_25	AC	2 ms; 4,348 KB
testcase_26	AC	13 ms; 4,348 KB
testcase_27	AC	2 ms; 4,348 KB
testcase_28	AC	41 ms; 4,348 KB
testcase_29	AC	2 ms; 4,348 KB

ソースコード

#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
#define cout_vector(x) rep(i,x.size()) cout << x[i] << ' ';
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; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

using mint = modint998244353;

mint f1(mint x){
    return x * (x+1) / mint(2);
}
mint f2(mint x){
    return x * (x+1) * (mint(2) * x + mint(1)) / mint(6);
}

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int N,M; cin >> N >> M;
    mint ans = 1;
    ans *= N;
    ans *= (N+1);
    ans *= M;
    int i = M;
    while(i){
        int v = N/i;
        int j = N/(v+1);
        ans -= mint(2 * N + 2) * mint(v) * (f1(mint(i)) - f1(mint(j)));
        ans += mint(v+1) * mint(v) * (f2(mint(i)) - f2(mint(j)));
        i = j;
    }
    ans /= mint(2);
    cout << ans << endl;
}