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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
#191006#6736. Alice and BobBbaka_#RE 10ms19312kbC++201.1kb2023-09-29 16:41:312023-09-29 16:41:31

Judging History

你现在查看的是最新测评结果

  • [2023-09-29 16:41:31]
  • 评测
  • 测评结果:RE
  • 用时:10ms
  • 内存:19312kb
  • [2023-09-29 16:41:31]
  • 提交

answer

#include <iostream>
#include <cmath>

using namespace std;
using ll = long long;
// #define int long long
const int mod = 998244353;
const int maxn = 1e6 + 10;
ll f[maxn],g[maxn];

ll qpow(ll n, ll m)
{
    n%=mod;
    ll res = 1;
    while(m)
    {
        if(m&1)
        {
            res = res*n%mod;
        }
        n = n*n%mod;
        m>>=1;
    }
    return res;
}
void init(void)
{
    f[0]=1;
    for(int i=1;i<maxn;i++)
    {
        f[i]=f[i-1]*i%mod;
    }
    g[maxn-1]=qpow(f[maxn-1],mod-2);
    for(int i=maxn-2;i>=1;i--)
    {
        g[i]=g[i+1]*(i+1)%mod;
    }
}
ll C(int n, int m)
{
    if(m==0||m==n)
    {
        return 1;
    }
    if(m<=0 || n < m)
    {
        return 0;
    }
    else
    {
        return f[n]*g[m]%mod*g[n-m]%mod;
    }
}
signed main()
{
    init();
    int n;
    cin >> n;

    ll ans = 0;
    for (int i = 1; i <= n; i++)
    {
        ans += C(n - i, i - 1) * f[i - 1] % mod * f[n - i] % mod;
        ans %= mod;
    }
    cout << ans << '\n';
    return 0;
}

詳細信息

Test #1:

score: 100
Accepted
time: 10ms
memory: 19300kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 10ms
memory: 19312kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 7ms
memory: 19308kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 3ms
memory: 19228kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 9ms
memory: 19308kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 6ms
memory: 19220kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 10ms
memory: 19244kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 7ms
memory: 19220kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 10ms
memory: 19224kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 7ms
memory: 19276kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 7ms
memory: 19312kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 10ms
memory: 19312kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 10ms
memory: 19216kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: -100
Runtime Error

input:

1361956

output:


result: