QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#24689#5. 在线 O(1) 逆元skip2004100 ✓3244ms19668kbC++20827b2022-04-02 11:07:352024-11-05 21:47:07

Judging History

你现在查看的是最新测评结果

  • [2024-11-05 21:47:07]
  • 管理员手动重测本题所有提交记录
  • 测评结果:100
  • 用时:3244ms
  • 内存:19668kb
  • [2024-11-05 21:43:31]
  • 管理员手动重测本题所有提交记录
  • 测评结果:100
  • 用时:4599ms
  • 内存:19680kb
  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2022-04-30 06:29:49]
  • 评测
  • 测评结果:100
  • 用时:4945ms
  • 内存:19480kb
  • [2022-04-02 11:07:35]
  • 提交

answer

#include<cmath>
#include<functional>
#include"inv.h"

const int mod = 998244353;
const int mod2 = 974849; 
const int w = sqrt(mod2);
const int limit = 3 * (w + 1) * 1024;
int djq[limit], arr[mod2];
using u64 = unsigned long long;
int inv(int x) {
	const int p = (u64) x * arr[x >> 10] % mod;
	return (u64) arr[x >> 10] * (p < limit ? djq[p] : mod - djq[mod - p]) % mod;
}
void init(int) {
	for(int i = w;i >= 1;--i) {
		std::function<int(int)> getinv = [&](int x) {
			return x == 1 ? 1 : mod2 - u64(mod2 / x) * getinv(mod2 % x) % mod2;
		};
		int inv = getinv(i);
		for(int j = 1;j <= w;++j) {
			arr[(u64) j * inv % mod2] = i;
			arr[mod2 - (u64) j * inv % mod2] = mod - i;
		}
	}
	arr[0] = 1, djq[1] = 1;
	for(int i = 2;i < limit;++i) {
		djq[i] = mod - u64(mod / i) * djq[mod % i] % mod;
	}
}

Details


Pretests


Final Tests

Test #1:

score: 10
Accepted
time: 22ms
memory: 19372kb

Test #2:

score: 20
Accepted
time: 293ms
memory: 19324kb

Test #3:

score: 30
Accepted
time: 1406ms
memory: 19668kb

Test #4:

score: 20
Accepted
time: 2463ms
memory: 19440kb

Test #5:

score: 20
Accepted
time: 3244ms
memory: 19320kb