QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#413306#6736. Alice and Bobgaotianyu#AC ✓115ms159884kbC++141.1kb2024-05-17 11:46:302024-05-17 11:46:31

Judging History

你现在查看的是最新测评结果

  • [2024-05-17 11:46:31]
  • 评测
  • 测评结果:AC
  • 用时:115ms
  • 内存:159884kb
  • [2024-05-17 11:46:30]
  • 提交

answer

#include <bits/stdc++.h>
#define int long long
#define endl "\n"

using namespace std;
typedef pair<int, int> PII;
const double epx = 1e-4;
const int mod = 998244353;
const int N = 1e7 + 10;
vector<int> x;
int n, fac[N], inv[N];

int qmi(int a, int b)
{
	int res = 1;
	while (b)
	{
		if (b & 1) res = (res * a) % mod;
		a = (a * a) % mod;
		b >>= 1;
	}
	return res % mod;
}

void init() {
	fac[0] = 1;
	for (int i = 1; i <= n; i++) fac[i] = (fac[i - 1] * i) % mod;
	inv[n] = qmi(fac[n], mod - 2);
	for (int i = n - 1; i >= 0; i -- ) {
		inv[i] = inv[i + 1] * (i + 1) % mod;
	}
}

int C(int n, int m)
{
	if (m > n) return 0;
	return ((fac[n] * inv[m] % mod) * inv[n - m]) % mod;
}

void solve()
{
	cin >> n;
//	n = 1e7;
	init();
	int ans = fac[n - 1];
	for (int i = 2; i <= n; i++)
	{
		if (n - i < i - 1) break;
		ans = (ans + (C(n - i, i - 1) * fac[i - 1] % mod) * fac[n - i]) % mod;
	}
	cout << (ans + mod) % mod << endl;
}


signed main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);

	int tt = 1;

//	cin>>tt;
	while (tt--) solve();
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 5700kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 0ms
memory: 5572kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 5644kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5604kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 0ms
memory: 5700kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5632kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5644kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 1ms
memory: 5572kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 0ms
memory: 5640kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 1ms
memory: 5632kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 5632kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5628kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 1ms
memory: 5624kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 15ms
memory: 27828kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 83ms
memory: 125596kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 85ms
memory: 132760kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 68ms
memory: 102740kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 48ms
memory: 60972kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 75ms
memory: 115552kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 36ms
memory: 52560kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 115ms
memory: 159828kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 107ms
memory: 159884kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 99ms
memory: 159756kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"