結果

問題 No.1889 K Consecutive Ks (Hard)
ユーザー ygussanyygussany
提出日時 2022-03-19 16:56:44
言語 C
(gcc 12.3.0)
結果
AC  
実行時間 1,857 ms / 6,000 ms
コード長 3,839 bytes
コンパイル時間 964 ms
コンパイル使用メモリ 39,016 KB
実行使用メモリ 26,368 KB
最終ジャッジ日時 2024-10-04 20:09:40
合計ジャッジ時間 22,348 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
6,016 KB
testcase_01 AC 2 ms
6,016 KB
testcase_02 AC 1,810 ms
26,240 KB
testcase_03 AC 3 ms
6,144 KB
testcase_04 AC 3 ms
6,016 KB
testcase_05 AC 2 ms
5,888 KB
testcase_06 AC 2 ms
6,144 KB
testcase_07 AC 2 ms
6,016 KB
testcase_08 AC 2 ms
6,144 KB
testcase_09 AC 1,621 ms
26,240 KB
testcase_10 AC 1,652 ms
26,240 KB
testcase_11 AC 233 ms
11,264 KB
testcase_12 AC 562 ms
16,256 KB
testcase_13 AC 414 ms
16,256 KB
testcase_14 AC 571 ms
16,256 KB
testcase_15 AC 989 ms
25,856 KB
testcase_16 AC 1,612 ms
26,240 KB
testcase_17 AC 268 ms
11,520 KB
testcase_18 AC 1,496 ms
26,112 KB
testcase_19 AC 1,617 ms
26,368 KB
testcase_20 AC 1,665 ms
26,240 KB
testcase_21 AC 1,658 ms
26,240 KB
testcase_22 AC 1,857 ms
26,240 KB
testcase_23 AC 854 ms
25,728 KB
testcase_24 AC 1,650 ms
26,240 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <stdio.h>

#define N_MAX 200000
#define M_MAX 200000
const int Mod = 998244353,
	bit[21] = {1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576},
	bit_inv[21] = {1, 499122177, 748683265, 873463809, 935854081, 967049217, 982646785, 990445569, 994344961, 996294657, 997269505, 997756929, 998000641, 998122497, 998183425, 998213889, 998229121, 998236737, 998240545, 998242449, 998243401},
	root[21] = {1, 998244352, 911660635, 372528824, 929031873, 452798380, 922799308, 781712469, 476477967, 166035806, 258648936, 584193783, 63912897, 350007156, 666702199, 968855178, 629671588, 24514907, 996173970, 363395222, 565042129},
	root_inv[21] = {1, 998244352, 86583718, 509520358, 337190230, 87557064, 609441965, 135236158, 304459705, 685443576, 381598368, 335559352, 129292727, 358024708, 814576206, 708402881, 283043518, 3707709, 121392023, 704923114, 950391366};
int ntt_b[20][524288], ntt_c[20][524288], ntt_x[20][524288], ntt_y[20][524288];

void NTT(int k, int a[], int z[])
{
	if (k == 0) {
		z[0] = a[0];
		return;
	}
	
	int i, d = bit[k-1], tmpp;
	long long tmp;
	for (i = 0; i < d; i++) {
		ntt_b[k][i] = a[i*2];
		ntt_c[k][i] = a[i*2+1];
	}
	NTT(k - 1, ntt_b[k], ntt_x[k]);
	NTT(k - 1, ntt_c[k], ntt_y[k]);
	for (i = 0, tmp = 1; i < d; i++, tmp = tmp * root[k] % Mod) {
		tmpp = tmp * ntt_y[k][i] % Mod;
		z[i] = ntt_x[k][i] + tmpp;
		if (z[i] >= Mod) z[i] -= Mod;
		z[i+d] = ntt_x[k][i] - tmpp;
		if (z[i+d] < 0) z[i+d] += Mod;
	}
}

void NTT_reverse(int k, int z[], int a[])
{
	if (k == 0) {
		a[0] = z[0];
		return;
	}
	
	int i, d = bit[k-1], tmpp;
	long long tmp;
	for (i = 0; i < d; i++) {
		ntt_x[k][i] = z[i*2];
		ntt_y[k][i] = z[i*2+1];
	}
	NTT_reverse(k - 1, ntt_x[k], ntt_b[k]);
	NTT_reverse(k - 1, ntt_y[k], ntt_c[k]);
	for (i = 0, tmp = 1; i < d; i++, tmp = tmp * root_inv[k] % Mod) {
		tmpp = tmp * ntt_c[k][i] % Mod;
		a[i] = ntt_b[k][i] + tmpp;
		if (a[i] >= Mod) a[i] -= Mod;
		a[i+d] = ntt_b[k][i] - tmpp;
		if (a[i+d] < 0) a[i+d] += Mod;
	}
}

// Compute the product of two polynomials a[0-da] and b[0-db] using NTT in O(d * log d) time
void prod_poly_NTT(int da, int db, int a[], int b[], int c[])
{
	int i, k;
	for (k = 0; bit[k] <= da + db; k++);
	for (i = da + 1; i < bit[k]; i++) a[i] = 0;
	for (i = db + 1; i < bit[k]; i++) b[i] = 0;
	
	static int x[524288], y[524288], z[524288];
	NTT(k, a, x);
	if (db == da) {
		for (i = 0; i <= da; i++) if (a[i] != b[i]) break;
		if (i <= da) NTT(k, b, y);
		else for (i = 0; i < bit[k]; i++) y[i] = x[i];
	} else NTT(k, b, y);
	for (i = 0; i < bit[k]; i++) z[i] = (long long)x[i] * y[i] % Mod;
	NTT_reverse(k, z, c);
	for (i = 0; i <= da + db; i++) c[i] = (long long)c[i] * bit_inv[k] % Mod;
}

long long pow_mod(int n, long long k)
{
	long long N, ans = 1;
	for (N = n; k > 0; k >>= 1, N = N * N % Mod) if (k & 1) ans = ans * N % Mod;
	return ans;
}

int solve_sqrt(int N, int M)
{
	const int THR = 10000;
	int i, j, d[524288] = {}, a[524288], b[524288], c[524288] = {};
	long long dp[N_MAX + 1], tmp, sum = 0;
	for (i = 2; i <= M; i++) for (j = i; j <= N; j += i) d[j]++;
	for (j = 0; j < THR; j++) b[j] = d[j];
	for (i = 1, dp[0] = 1; i <= N; i++) {
		if (i % THR == 0) {
			for (j = (i - 1) / THR * THR; j < i; j++) {
				a[j] = dp[j];
				b[j+THR] = d[j+THR];
			}
			prod_poly_NTT(i - 1, i - 1 + THR, a, b, c);
		}
		for (j = i / THR * THR, tmp = c[i]; j < i - 1; j++) tmp += dp[j] * d[i-j];
		tmp %= Mod;
		dp[i] = pow_mod(M - 1, i) - (sum + tmp) % Mod;
		if (dp[i] < 0) dp[i] += Mod;
		sum = (sum * (M - 1) + tmp * (M - 2)) % Mod;
	}
	return (pow_mod(M, N) - dp[N] % Mod + Mod) % Mod;
}

int main()
{
	int N, M;
	scanf("%d %d", &N, &M);
	printf("%d\n", solve_sqrt(N, M));
	fflush(stdout);
	return 0;
}
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