#952010 (C++23) No.2633 Subsequence Combination Score

• 問題: No.2633 Subsequence Combination Score
• ユーザー: kwm_t
• 提出日時: 2024-02-17 16:43:32
• 言語: C++23 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 203 ms / 2,000 ms
• コード長: 3,042 bytes
• コンパイル時間: 5,094 ms
• コンパイル使用メモリ: 317,680 KB
• 実行使用メモリ: 23,576 KB
• 最終ジャッジ日時: 2024-02-17 16:43:47
• 合計ジャッジ時間: 12,827 ms
• ジャッジサーバーID （参考情報）: judge14 / judge16

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	24 ms; 18,928 KB
testcase_01	AC	24 ms; 19,056 KB
testcase_02	AC	44 ms; 21,568 KB
testcase_03	AC	137 ms; 22,456 KB
testcase_04	AC	147 ms; 22,432 KB
testcase_05	AC	127 ms; 22,420 KB
testcase_06	AC	142 ms; 22,316 KB
testcase_07	AC	133 ms; 22,364 KB
testcase_08	AC	45 ms; 19,824 KB
testcase_09	AC	186 ms; 23,160 KB
testcase_10	AC	178 ms; 23,088 KB
testcase_11	AC	179 ms; 23,064 KB
testcase_12	AC	180 ms; 22,984 KB
testcase_13	AC	179 ms; 23,088 KB
testcase_14	AC	181 ms; 22,992 KB
testcase_15	AC	203 ms; 23,256 KB
testcase_16	AC	181 ms; 23,048 KB
testcase_17	AC	180 ms; 23,012 KB
testcase_18	AC	178 ms; 22,984 KB
testcase_19	AC	178 ms; 23,576 KB
testcase_20	AC	179 ms; 23,492 KB
testcase_21	AC	174 ms; 23,380 KB
testcase_22	AC	172 ms; 23,524 KB
testcase_23	AC	172 ms; 23,320 KB
testcase_24	AC	173 ms; 23,356 KB
testcase_25	AC	182 ms; 23,360 KB
testcase_26	AC	171 ms; 23,216 KB
testcase_27	AC	159 ms; 23,148 KB
testcase_28	AC	166 ms; 23,136 KB
testcase_29	AC	27 ms; 18,928 KB
testcase_30	AC	24 ms; 18,928 KB
testcase_31	AC	23 ms; 18,928 KB
testcase_32	AC	23 ms; 18,928 KB
testcase_33	AC	177 ms; 22,940 KB
testcase_34	AC	183 ms; 22,940 KB
testcase_35	AC	177 ms; 22,940 KB
testcase_36	AC	178 ms; 23,208 KB
testcase_37	AC	182 ms; 23,080 KB
testcase_38	AC	180 ms; 23,108 KB
testcase_39	AC	203 ms; 23,024 KB
testcase_40	AC	181 ms; 23,004 KB

ソースコード

#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
const int mod = 998244353;
//using mint = modint1000000007;
//const int mod = 1000000007;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
// combination mod prime
// https://www.youtube.com/watch?v=8uowVvQ_-Mo&feature=youtu.be&t=1619
struct combination {
	std::vector<mint> fact, ifact;
	combination(int n) :fact(n + 1), ifact(n + 1) {
		assert(n < mod);
		fact[0] = 1;
		for (int i = 1; i <= n; ++i) fact[i] = fact[i - 1] * i;
		ifact[n] = fact[n].inv();
		for (int i = n; i >= 1; --i) ifact[i - 1] = ifact[i] * i;
	}
	mint operator()(int n, int k) { return com(n, k); }
	mint com(int n, int k) {
		//負の二項係数を考慮する場合にコメントアウトを外す
		//if (n < 0) return com(-n, k) * (k % 2 ? -1 : 1);
		if (k < 0 || k > n) return 0;
		return fact[n] * ifact[k] * ifact[n - k];
	}
	mint comsub(long long n, long long k) {
		if (n - k < k) k = n - k;
		assert(k < (int)fact.size());
		mint val = ifact[k];
		for (int i = 0; i < k; ++i) val *= n - i;
		return val;
	}
	template <typename ...Ms, std::enable_if_t<std::conjunction_v<std::is_integral<Ms>...>, std::nullptr_t> = nullptr>
	mint polynom(const int n, const Ms & ...ms) {
		mint res = fact[n];
		int sum = 0;
		for (int m : { ms... }) {
			if (m < 0 or m > n) return 0;
			res *= ifact[m];
			sum += m;
		}
		if (sum > n)return 0;
		res *= ifact[n - sum];
		return res;
	}
	mint div(int x) {
		if (x >= (int)fact.size())return mint(x).inv();
		return fact[x - 1] * ifact[x];
	}
	mint inv(int n, int k) {
		//if (n < 0) return inv(-n, k) * (k % 2 ? -1 : 1);
		if (k < 0 || k > n) return 0;
		return ifact[n] * fact[k] * fact[n - k];
	}
	mint p(int n, int k) { return fact[n] * ifact[n - k]; }
}c(2000006);
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n; cin >> n;
	vector<int>a(n);
	rep(i, n)cin >> a[i];
	//分割統治FFTをするだけでは？
	mint ans = 0;
	vector<mint>dp(n);
	auto f = [&](auto self, int l, int r)->void {
		if (l + 1 == r) {
			dp[l] += c.fact[a[l]];
			ans += dp[l] * c.ifact[a[l]];
			return;
		}
		int m = (l + r) / 2;
		self(self, l, m);
		vector<mint>x(a[l] - a[m - 1] + 1);
		rep2(i, l, m)x[a[l] - a[i]] += dp[i];
		vector<mint>y(a[l] - a[r - 1] + 1);
		rep(i, y.size())y[i] = c.ifact[i];
		auto z = convolution(x, y);
		rep2(i, m, r)dp[i] += z[a[l] - a[i]];
		self(self, m, r);
	};
	f(f, 0, n);
	cout << ans.val() << endl;
	return 0;
}