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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#344824#6736. Alice and Bobwzihan#AC ✓126ms159900kbC++201.1kb2024-03-05 14:30:002024-03-05 14:30:01

Judging History

你现在查看的是最新测评结果

  • [2024-03-05 14:30:01]
  • 评测
  • 测评结果:AC
  • 用时:126ms
  • 内存:159900kb
  • [2024-03-05 14:30:00]
  • 提交

answer

#include<bits/stdc++.h>
#define int long long 
#define endl "\n"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const int N = 1e7 + 10, inf = 0x3f3f3f3f;
const long long INF = 0x3f3f3f3f3f3f3f3f; 

const int mod = 998244353;

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;
}
int fac[N], invfac[N];
int C(int a, int b) {
	if (a < 0 || b < 0 || b > a) return 0;
	return fac[a] * invfac[b] % mod * invfac[a - b] % mod;
}
void solve() {
	int n;
	cin >> n;
	
	fac[0] = 1;
	for (int i = 1; i <= n; i++) fac[i] = fac[i - 1] * i % mod;
	invfac[n] = qmi(fac[n], mod - 2);
	
	for (int i = n - 1; i >= 0; i--) invfac[i] = invfac[i + 1] * (i + 1) % mod;
	
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		ans += C(n - i, i - 1) * fac[i - 1] % mod * fac[n - i] % mod;
		ans %= mod; 
	}
	cout << ans << endl;
}
signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int t = 1;
	
	// cin >> t;
	for(int i = 1; i <= t; i ++ ) {
		solve();
	}
	
} 

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 5728kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

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

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 5700kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5748kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 0ms
memory: 5664kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5660kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5684kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 1ms
memory: 5724kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 0ms
memory: 5728kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 1ms
memory: 5732kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 5616kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5740kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 1ms
memory: 5728kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 17ms
memory: 27888kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 94ms
memory: 124356kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 97ms
memory: 133340kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 57ms
memory: 101092kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 37ms
memory: 60936kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 89ms
memory: 114248kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 18ms
memory: 51864kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 126ms
memory: 159820kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 67ms
memory: 159876kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 114ms
memory: 159900kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"