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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
#412806#6736. Alice and Bobwdbl857#AC ✓116ms159864kbC++201.3kb2024-05-16 19:43:522024-05-16 19:43:53

Judging History

你现在查看的是最新测评结果

  • [2024-05-16 19:43:53]
  • 评测
  • 测评结果:AC
  • 用时:116ms
  • 内存:159864kb
  • [2024-05-16 19:43:52]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
#define ios ios::sync_with_stdio(false), cin.tie(nullptr);
#define int long long
#define ll long long
#define int128 __int128
#define ull unsigned long long
#define endl "\n"
#define pi acos(-1)
typedef pair<int, int> pii;
const double eps = 1e-6;
const int N = 1e7 + 10, M = 1010, INF = 1e18;
const int mod = 998244353;

int p[N];
int inv[N];

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

void init(int n)
{
    p[0]=1;
    for(int i=1;i<=n;i++)
    {
        p[i]=p[i-1]*i%mod;
    }
    inv[n]=qmi(p[n],mod-2);
    for(int i=n-1;i>=0;i--) inv[i]=inv[i+1]*(i+1)%mod;
}

int C(int a,int b)
{
    int x=inv[b]*inv[a-b]%mod;
    return p[a]*x%mod;
}
void solve()
{
    init(1e7+7);
    int n;
    cin>>n;
    int ans=0;
    for(int i=1;i<=(n+1)/2;i++)
    {
        int x=p[n-i]*p[i-1]%mod;
        ans=(ans+x*C(n-i,i-1)%mod+mod)%mod;
    }
    cout<<ans<<endl;
}
signed main()
{
    ios;
    int T = 1;
    // cin >> T;
    // cout << fixed << setprecision(8);
    for (int i = 1; i <= T; i++)
    {
        // cout << "Case " << i << ": ";
        solve();
    }

    return 0;
}

详细

Test #1:

score: 100
Accepted
time: 83ms
memory: 159780kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 75ms
memory: 159756kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 83ms
memory: 159864kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 80ms
memory: 159784kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 83ms
memory: 159720kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 87ms
memory: 159676kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 72ms
memory: 159748kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 79ms
memory: 159864kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 88ms
memory: 159680kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 90ms
memory: 159852kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 74ms
memory: 159836kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 83ms
memory: 159816kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 83ms
memory: 159780kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 86ms
memory: 159840kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 104ms
memory: 159688kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 111ms
memory: 159720kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 101ms
memory: 159840kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 88ms
memory: 159676kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 91ms
memory: 159720kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 86ms
memory: 159856kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 116ms
memory: 159784kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 116ms
memory: 159692kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 109ms
memory: 159716kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"