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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#418608#6736. Alice and BobAndeviking#AC ✓105ms159976kbC++20991b2024-05-23 14:47:142024-05-23 14:47:15

Judging History

你现在查看的是最新测评结果

  • [2024-05-23 14:47:15]
  • 评测
  • 测评结果:AC
  • 用时:105ms
  • 内存:159976kb
  • [2024-05-23 14:47:14]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define range(x) (x).begin(),(x).end()
const int dir[][2]={1,0,-1,0,0,1,0,-1};
const ll mod=998244353;

const ll N=10000005;
ll fac[N],ifac[N];
ll qpow(ll a,ll b)
{
    ll ans=1;
    for(;b;b>>=1){
        if(b&1)
            ans=ans*a%mod;
        a=a*a%mod;
    }

    return ans;
}
void solve()
{
    int n;
    cin>>n;

    fac[0]=1;
    for(int i=1;i<=n;++i)
        fac[i]=fac[i-1]*i%mod;

    ifac[n]=qpow(fac[n],mod-2);
    for(int i=n-1;~i;--i)
        ifac[i]=ifac[i+1]*(i+1)%mod;

    ll ans=0;
    for(int i=1;i<=(n+1)/2;++i){
        (ans+=fac[n-i]*fac[n-i]%mod*ifac[n-2*i+1]%mod)%=mod;
        // cout<<fac[n-i]*ifac[n-2*i+1]%mod<<'\n';
    }

    cout<<ans<<'\n';
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--)
        solve();
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 5592kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 1ms
memory: 5696kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 5788kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5648kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 5720kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5708kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5656kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 1ms
memory: 5780kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 1ms
memory: 5772kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 0ms
memory: 5720kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 5784kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5720kb

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: 18ms
memory: 27832kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 80ms
memory: 125156kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 75ms
memory: 133040kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 66ms
memory: 102096kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 30ms
memory: 61176kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 68ms
memory: 114440kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 22ms
memory: 52112kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 105ms
memory: 159912kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 99ms
memory: 159976kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 101ms
memory: 159928kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"