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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#356323#6736. Alice and Bobstar_xiao#AC ✓623ms83560kbC++231.0kb2024-03-17 17:33:452024-03-17 17:33:45

Judging History

你现在查看的是最新测评结果

  • [2024-03-17 17:33:45]
  • 评测
  • 测评结果:AC
  • 用时:623ms
  • 内存:83560kb
  • [2024-03-17 17:33:45]
  • 提交

answer

#include<bits/stdc++.h>

using namespace std;

//int n;
const int N=1e7+10;
#define int long long 
const int mod=998244353;

int sum[N];
int fac[N],infac[N];
int n;

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

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

int C(int a,int b)
{
	return fac[b]*infac[a]%mod*infac[b-a]%mod;
}


void solve()
{
	int ans=0;
	scanf("%lld",&n);
	sum[0]=1ll;
	//init();
	//cout<<C(3,2);
	for(int i=1;i<=n;i++)
	{
		//ans=ans*i%mod;
		sum[i]=sum[i-1]*i%mod;
	}
	//sum[0]=0;
	ans=(sum[n-1])%mod;
	for(int i=2;i<=n;i++)
	{
		if(i-1>n-i) break;
		ans=(ans+sum[n-i]%mod*qmi(sum[n-i-(i-1)],mod-2)%mod*sum[n-i]%mod+mod)%mod;
		//cout<<ans<<'\n';
	}
	printf("%lld\n",(ans+mod)%mod);
	
}
signed main()
{
	//ios::sync_with_stdio(false);
	//cin.tie(0),cout.tie(0);
	
	solve();
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 5948kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 1ms
memory: 5916kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 6004kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5912kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 5940kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5952kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5952kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 1ms
memory: 5876kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 1ms
memory: 5880kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 0ms
memory: 5896kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 0ms
memory: 5864kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 0ms
memory: 5872kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 0ms
memory: 6008kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 86ms
memory: 16200kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 460ms
memory: 63220kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 511ms
memory: 69432kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 361ms
memory: 53100kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 217ms
memory: 32440kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 429ms
memory: 61244kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 182ms
memory: 28380kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 607ms
memory: 83560kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 623ms
memory: 82796kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 606ms
memory: 82688kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"