結果
問題 | No.2336 Do you like typical problems? |
ユーザー |
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提出日時 | 2023-06-02 23:02:25 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 468 ms / 2,000 ms |
コード長 | 1,937 bytes |
コンパイル時間 | 4,272 ms |
コンパイル使用メモリ | 258,524 KB |
最終ジャッジ日時 | 2025-02-13 20:03:31 |
ジャッジサーバーID (参考情報) |
judge3 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 18 |
ソースコード
#include<bits/stdc++.h>#include<atcoder/all>using namespace std;using namespace atcoder;typedef modint998244353 mint;typedef long long ll;//defmodfactconst int COMinitMAX = 998244;mint fact[COMinitMAX+1], factinv[COMinitMAX+1];void modfact(){fact[0] = 1;for (int i=1; i<=COMinitMAX; i++){fact[i] = fact[i-1] * i;}factinv[COMinitMAX] = fact[COMinitMAX].inv();for (int i=COMinitMAX-1; i>=0; i--){factinv[i] = factinv[i+1] * (i+1);}}mint cmb(int a, int b){if (a<b || b<0) return mint(0);return fact[a]*factinv[b]*factinv[a-b];}//--------// defcomptemplate <typename T>vector<T> compress(vector<T> &X) {vector<T> vals = X;sort(vals.begin(), vals.end());vals.erase(unique(vals.begin(), vals.end()), vals.end());return vals;}// -----// importbisecttemplate <typename T>int bisect_left(vector<T> &X, T v){return lower_bound(X.begin(), X.end(), v) - X.begin();}template <typename T>int bisect_right(vector<T> &X, T v){return upper_bound(X.begin(), X.end(), v) - X.begin();}// -----int main(){modfact();int n;cin >> n;vector<int> b(n), c(n);vector<int> val;for (int i=0; i<n; i++){cin >> b[i] >> c[i];b[i]--;val.push_back(b[i]);val.push_back(c[i]);}vector<int> v = compress(val);int m = v.size();vector<mint> imos(m + 1);for (int i=0; i<n; i++){imos[bisect_left(v, b[i])] += mint(1) / mint(c[i] - b[i]);imos[bisect_left(v, c[i])] -= mint(1) / mint(c[i] - b[i]);}for (int i=0; i<m; i++){imos[i+1] += imos[i];}mint nowval = 0;mint ret = 0;for (int i=0; i<m-1; i++){ret += imos[i] * (v[i+1] - v[i]) * (nowval * 2 + imos[i] * (v[i+1] - v[i] - 1)) / 2;nowval += imos[i] * (v[i+1] - v[i]);//cout << ret.val() << endl;//cout << ret.val() << endl;}for (int i=0; i<n; i++){ret -= mint(c[i] - b[i] - 1) / 2 / mint(c[i] - b[i]);}//cout << ret.val() << endl;ret *= fact[n] / 2;cout << ret.val() << endl;}