#793261 (C++17) No.2058 Binary String

• 問題: No.2058 Binary String
• ユーザー: square1001
• 提出日時: 2022-08-26 23:43:26
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 7 ms / 2,000 ms
• コード長: 1,359 bytes
• コンパイル時間: 4,063 ms
• コンパイル使用メモリ: 156,564 KB
• 実行使用メモリ: 5,888 KB
• 最終ジャッジ日時: 2024-10-14 00:26:54
• 合計ジャッジ時間: 4,918 ms
• ジャッジサーバーID （参考情報）: judge4 / judge5

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	1 ms; 5,248 KB
testcase_01	AC	2 ms; 5,248 KB
testcase_02	AC	5 ms; 5,888 KB
testcase_03	AC	2 ms; 5,248 KB
testcase_04	AC	2 ms; 5,248 KB
testcase_05	AC	2 ms; 5,248 KB
testcase_06	AC	2 ms; 5,248 KB
testcase_07	AC	6 ms; 5,760 KB
testcase_08	AC	3 ms; 5,248 KB
testcase_09	AC	6 ms; 5,760 KB
testcase_10	AC	4 ms; 5,248 KB
testcase_11	AC	3 ms; 5,248 KB
testcase_12	AC	4 ms; 5,248 KB
testcase_13	AC	4 ms; 5,248 KB
testcase_14	AC	3 ms; 5,248 KB
testcase_15	AC	3 ms; 5,248 KB
testcase_16	AC	3 ms; 5,248 KB
testcase_17	AC	4 ms; 5,248 KB
testcase_18	AC	2 ms; 5,248 KB
testcase_19	AC	6 ms; 5,888 KB
testcase_20	AC	6 ms; 5,248 KB
testcase_21	AC	7 ms; 5,888 KB
testcase_22	AC	7 ms; 5,760 KB
testcase_23	AC	7 ms; 5,760 KB
testcase_24	AC	7 ms; 5,760 KB
testcase_25	AC	7 ms; 5,760 KB

ソースコード

/*
	The technique on "constexpr" is derived from:
	https://atcoder.jp/contests/agc023/submissions/2435844
*/

#include <iostream>

constexpr int MOD = 998244353;

template<int N> class precalculation {
public:
	int inv[N];
	int d[N];
	constexpr precalculation() : inv(), d() {
		inv[1] = 1;
		for (int i = 2; i < N; i++) {
			inv[i] = (long long)(inv[MOD % i]) * (MOD - MOD / i) % MOD;
		}
		for (int i = 1; i < N; i++) {
			d[i] = 1;
		}
		for (int i = 2; i < N; i++) {
			if (d[i] == 1) {
				for (int j = i * 2; j < N; j += i) {
					if (d[j] == 1) {
						d[j] = i;
					}
				}
			}
		}
	}
};

constexpr precalculation precalc = precalculation<200001>();

int modpow(int a, int b) {
	int answer = 1;
	while (b != 0) {
		if ((b & 1) == 1) {
			answer = (long long)(answer) * a % MOD;
		}
		a = (long long)(a) * a % MOD;
		b >>= 1;
	}
	return answer;
}

int p[200009];
int main() {
	int N, K;
	std::cin >> N >> K;
	N -= 1;
	for (int i = 1; i <= N; i++) {
		if (precalc.d[i] == 1) {
			p[i] = modpow(i, K);
		}
		else {
			p[i] = (long long)(p[precalc.d[i]]) * p[i / precalc.d[i]] % MOD;
		}
	}
	int mult = 1;
	int answer = 0;
	for (int i = 0; i <= N; i++) {
		answer = (answer + (long long)(p[i]) * mult) % MOD;
		mult = (long long)(mult) * (N - i) % MOD;
		mult = (long long)(mult) * precalc.inv[i + 1] % MOD;
	}
	std::cout << answer << '\n';
	return 0;
}