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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#236136#6736. Alice and BobchunzhifengAC ✓117ms81828kbC++14906b2023-11-03 16:56:302023-11-03 16:56:30

Judging History

你现在查看的是最新测评结果

  • [2023-11-03 16:56:30]
  • 评测
  • 测评结果:AC
  • 用时:117ms
  • 内存:81828kb
  • [2023-11-03 16:56:30]
  • 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=0x3f3f3f3f3f3f3f3f;
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(){
	init();
	int n; cin>>n;
	ll ans=0;
	for(int i=1;i<=n;i++){
		(ans+=C(n-i,i-1)*fac[i-1]%mod*fac[n-i])%=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();
}

详细

Test #1:

score: 100
Accepted
time: 89ms
memory: 81672kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 78ms
memory: 81752kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 81ms
memory: 81764kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 85ms
memory: 81740kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 76ms
memory: 81736kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 80ms
memory: 81756kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 85ms
memory: 81828kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 80ms
memory: 81736kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 81ms
memory: 81700kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 88ms
memory: 81704kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 88ms
memory: 81760kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 89ms
memory: 81672kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 89ms
memory: 81740kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 85ms
memory: 81752kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 102ms
memory: 81676kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 109ms
memory: 81760kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 102ms
memory: 81700kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 87ms
memory: 81732kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 109ms
memory: 81760kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 92ms
memory: 81824kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 110ms
memory: 81656kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 110ms
memory: 81728kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 117ms
memory: 81768kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"