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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#233101#6736. Alice and Bobmuxiuyulin#AC ✓125ms81800kbC++20923b2023-10-31 13:18:222023-10-31 13:18:23

Judging History

你现在查看的是最新测评结果

  • [2023-10-31 13:18:23]
  • 评测
  • 测评结果:AC
  • 用时:125ms
  • 内存:81800kb
  • [2023-10-31 13:18:22]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned ll
#define endl "\n"
#define PII pair<int,int>
const ll INF=0x3f3f3f3f;//3f3f3f3f;
const int mod=998244353;
const int N=1e7+5;
int fac[N],infac[N];
ll ksm(ll a,ll n){
	ll res=1;
	while(n){
		if(n&1) res=res*a%mod;
		a=a*a%mod; n>>=1;
	} return res;
}
void init(){
	fac[0]=infac[0]=1;
	for(int i=1;i<N;i++) fac[i]=1LL*fac[i-1]*i%mod;
	infac[N-1]=ksm(fac[N-1],mod-2);
	for(int i=N-2;i>=1;i--) infac[i]=1LL*infac[i+1]*(i+1)%mod;
}
ll C(int a,int b){
	if(a<b||b<0||a<0) return 0; 
	return 1LL*fac[a]*infac[b]%mod*infac[a-b]%mod;
}
void solve(){
    ll ans=0;
    init();
    int n; cin>>n;
    for(int i=1;i<=n;i++){
    	(ans+=C(n-i,i-1)*fac[i-1]%mod*fac[n-i]%mod)%=mod;
	} cout<<ans<<endl;
}
int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	int T=1; //cin>>T;
	while(T--) solve();
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 84ms
memory: 81756kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 80ms
memory: 81752kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 84ms
memory: 81676kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 76ms
memory: 81744kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 80ms
memory: 81740kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 81ms
memory: 81704kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 84ms
memory: 81764kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 84ms
memory: 81748kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 81ms
memory: 81676kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 88ms
memory: 81764kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 73ms
memory: 81704kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 88ms
memory: 81732kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 88ms
memory: 81736kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 93ms
memory: 81800kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 108ms
memory: 81680kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 114ms
memory: 81752kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 98ms
memory: 81736kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 103ms
memory: 81728kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 102ms
memory: 81744kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 95ms
memory: 81700kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 116ms
memory: 81800kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 113ms
memory: 81764kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 125ms
memory: 81748kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"