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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#404894#6736. Alice and BobqzuserAC ✓618ms83732kbC++17871b2024-05-04 21:36:002024-05-04 21:36:01

Judging History

你现在查看的是最新测评结果

  • [2024-05-04 21:36:01]
  • 评测
  • 测评结果:AC
  • 用时:618ms
  • 内存:83732kb
  • [2024-05-04 21:36:00]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 998244353;
const int N = 1e7 + 10; 
int f[N],inv[N];

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

signed main()
{
    f[0]=1;
    f[1]=1;
    inv[0]=1;
    inv[1]=1;
    for(int i=2;i<=N-1;i++){
        f[i]=f[i-1]*i%mod;
        //inv[i]=inv[i-1]*qmi(i,mod-2)%mod;
    }
    int n;cin>>n;
    int ans=0;
    for(int i=1;i<=n;i++){
        if(n-2*i+2>0){
            int bd = 1;
            bd = bd * f[n - i] % mod * qmi(f[n - 2 * i + 1], mod - 2) % mod;
            // for(int j=n-2*i+2;j<=n-i;j++){
            //     bd=bd*j%mod;
            // }
            ans=ans+f[n-i]*bd%mod;
        }
    }
    cout<<ans%mod;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 49ms
memory: 83540kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 40ms
memory: 82800kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 52ms
memory: 83580kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 53ms
memory: 83052kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 8ms
memory: 83024kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 53ms
memory: 83212kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 47ms
memory: 81824kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 52ms
memory: 83572kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 48ms
memory: 81708kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 53ms
memory: 82548kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 12ms
memory: 81956kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 52ms
memory: 82204kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 52ms
memory: 81768kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 129ms
memory: 81768kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 470ms
memory: 82728kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 486ms
memory: 82260kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 396ms
memory: 83720kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 251ms
memory: 83732kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 440ms
memory: 81912kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 171ms
memory: 83060kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 618ms
memory: 81928kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 611ms
memory: 82440kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 611ms
memory: 83720kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"