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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#379288#6736. Alice and BobRykonyAC ✓655ms81828kbC++20851b2024-04-06 16:56:242024-04-06 16:56:24

Judging History

你现在查看的是最新测评结果

  • [2024-04-06 16:56:24]
  • 评测
  • 测评结果:AC
  • 用时:655ms
  • 内存:81828kb
  • [2024-04-06 16:56:24]
  • 提交

answer

#include <bits/stdc++.h>

using namespace std;
#define int long long
const int mod=998244353;
const int maxn=1e7+10;
int a[maxn];

int qpow(int a,int n)
{
	int ans=1;
	while (n){
		if (n&1) ans=ans*a%mod;
		a=a*a%mod;
		n>>=1;
	}
	return ans;
}

void init()
{
	a[0]=1;
	for (int i=1;i<maxn;i++){
		a[i]=a[i-1]*i%mod;
	}
}

signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	int _=1;
//	cin>>_;
	init();
	while (_--){
		int n;
		cin>>n;
		int ans=1;
		for (int i=1;i<=n-1;i++) ans=ans*i%mod;
		int d=n-2,mn=n-2;
		for (int i=2;i<=n;i++){
			if (i==2){
				ans=(ans+a[n-i]*d)%mod;
			}
			else{
				if (mn-2<=0) break;
//				cout<<d<<'\n';
				d=d*qpow(n-i+1,mod-2)%mod;
				d=d*(mn-1)%mod*(mn-2)%mod;
				mn-=2;
				ans=(ans+d*a[n-i]%mod)%mod;
			}
		}
		cout<<ans<<'\n';
	}
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 52ms
memory: 81628kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 31ms
memory: 81620kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 48ms
memory: 81688kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 28ms
memory: 81736kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 43ms
memory: 81732kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 39ms
memory: 81732kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 48ms
memory: 81740kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 47ms
memory: 81728kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 45ms
memory: 81820kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 24ms
memory: 81732kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 39ms
memory: 81804kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 47ms
memory: 81732kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 33ms
memory: 81828kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 134ms
memory: 81744kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 501ms
memory: 81684kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 545ms
memory: 81768kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 411ms
memory: 81788kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 251ms
memory: 81736kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 461ms
memory: 81792kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 214ms
memory: 81744kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 629ms
memory: 81728kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 636ms
memory: 81792kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 655ms
memory: 81728kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"