結果
問題 | No.3106 Simple Math Problem 3 |
ユーザー |
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提出日時 | 2025-04-11 23:08:46 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 142 ms / 2,000 ms |
コード長 | 4,045 bytes |
コンパイル時間 | 2,071 ms |
コンパイル使用メモリ | 199,780 KB |
実行使用メモリ | 18,972 KB |
最終ジャッジ日時 | 2025-04-11 23:08:56 |
合計ジャッジ時間 | 6,948 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 4 |
other | AC * 42 |
ソースコード
#include <bits/stdc++.h> using namespace std; using ll=long long; const ll ILL=2167167167167167167; const int INF=2100000000; #define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++) #define all(p) p.begin(),p.end() template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>; template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;} template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;} template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());} template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;} template<class T> void vec_out(vector<T> &p,int ty=0){ if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";} else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}} template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;} template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;} template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;} int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;} template<class T> T square(T a){return a * a;} #include <atcoder/modint> using mint = atcoder::modint998244353; void solve(); // CITRUS CURIO CITY / FREDERIC int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t = 1; // cin >> t; rep(i, 0, t) solve(); } void solve(){ ll N; cin >> N; mint ans = 0; /*rep(s, 1, N + 1) rep(t, s, N + 1){ ll tmp = (N - s) / t - s; ans += max(0ll, tmp) * s; }*/ vector<ll> L(1), R(1); for (ll s = 1; s * s <= N; s++){ ll l = s; // (N - s) / t - s >= 0 // N - s >= s * t // (N - s) / s >= t ll r = (N - s) / s + 1; /* mint tmp = 0; for (ll k = l; k < r; k++){ tmp += (N - s) / k; } ans -= s * s * (r - l); ans += tmp * s; */ if (l >= r) break; L.push_back(l); R.push_back(r); ans -= s * s * (r - l); } if ((int)L.size() == 1){ cout << "0\n"; return; } mint inv2 = 2; inv2 = inv2.inv(); ll lim = L.back(); // 1 ~ lim for (ll t = 1; t <= lim; t++){ // rep(s, 1, t + 1) ans += ((N - s) / t) * s; ll tmpl = 1; while (tmpl != t + 1){ ll v = (N - tmpl) / t; ll tmpr = N - v * t; chmin(tmpr, t); ans += (mint)((N - tmpl) / t) * (mint)(tmpl + tmpr) * (mint)(tmpr - tmpl + 1) * inv2; tmpl = tmpr + 1; } } // cout << ans.val() << "\n"; // (lim + 1) ~ (N - 2) /* mint v1 = ans; for (ll s = 2; s <= lim; s++){ for (ll t = lim + 1; t < R[s]; t++){ ans += (N - s) / t * s; cout << t << " " << (N - s) / t * s << "\n"; } } cout << (ans - v1).val() << "\n"; v1 = ans;*/ ll v_max = (N - 1) / (lim + 1); for (ll v = 1; v <= v_max; v++){ // ans -= (mint)(v) * (mint)(1 + v) * (mint)(lim) * inv2; ll l = 1; while (l <= v){ ll t = (N - l) / v; if (t <= lim) break; // t * v = N - l ll r = N - t * v; chmin(r, v); // cout << v << " " << t << " "; // cout << ans.val() << endl; ans += (mint)(r - l + 1) * (r + l) * inv2 * (t - lim); l = r + 1; } } rep(s, 1, lim + 1){ ans += (mint)(s - 1) * (mint)(s) * (R[s] - 1 - lim); } cout << ans.val() << "\n"; }