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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#413425#6736. Alice and BobSSHL#WA 107ms159956kbC++141.1kb2024-05-17 15:15:072024-05-17 15:15:08

Judging History

你现在查看的是最新测评结果

  • [2024-05-17 15:15:08]
  • 评测
  • 测评结果:WA
  • 用时:107ms
  • 内存:159956kb
  • [2024-05-17 15:15:07]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr int N=1e5+1;
constexpr ll mod=998244353;
constexpr int maxn=1e7;
ll fac[maxn],inv[maxn];
ll pow(ll a,ll b)
{
    ll res=1;
    a%=mod;
    while(b)
    {
        if(b&1)
        res=res*a%mod;
        a=a*a%mod;
        b>>=1;
    }
    return res;
}
void pre()
{
    fac[0]=1;
    for(int i=1;i<maxn;i++)
    {
        fac[i]=fac[i-1]*i%mod;

    }
    inv[maxn-1]=pow(fac[maxn-1],mod-2);
    for(int i=maxn-2;i>=0;i--)
    {
        inv[i]=inv[i+1]*(i+1)%mod;
    }
}
ll c(ll a,ll b)
{
    if(b>a||b<0)
    return 0;
    return fac[a]*inv[b]%mod*inv[a-b]%mod;
}
void solve()
{
    pre();
    ll n;
    cin>>n;
    ll ans=0;
    if(n==1)
    {
        cout<<1;
        return;
    }
    for(int i=1;i<=n/2;i++)
    {
        ans+=((c(n-i,i-1)*fac[n-i])%mod*fac[i-1])%mod;
        ans%=mod;
        // cout<<c(n-i,i-1)<<' '<<fac[n-i]<<'\n';
    }
    cout<<ans%mod;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    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: 81ms
memory: 159948kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 79ms
memory: 159888kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 88ms
memory: 159888kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 85ms
memory: 159940kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 87ms
memory: 159860kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 80ms
memory: 159940kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 87ms
memory: 159816kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 83ms
memory: 159772kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 93ms
memory: 159856kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 77ms
memory: 159952kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 75ms
memory: 159956kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 89ms
memory: 159952kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 96ms
memory: 159884kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 96ms
memory: 159824kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: -100
Wrong Answer
time: 107ms
memory: 159872kb

input:

7579013

output:

693151411

result:

wrong answer 1st numbers differ - expected: '827172636', found: '693151411'