QOJ.ac

QOJ

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
#364560#6736. Alice and BobAtmizz#TL 14ms3804kbC++201.0kb2024-03-24 15:17:522024-03-24 15:17:52

Judging History

你现在查看的是最新测评结果

  • [2024-03-24 15:17:52]
  • 评测
  • 测评结果:TL
  • 用时:14ms
  • 内存:3804kb
  • [2024-03-24 15:17:52]
  • 提交

answer

#include <bits/stdc++.h>

using namespace std;
const int mod = 998244353;
typedef long long LL;
#define int long long


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


int C(int a, int b, int p)
{
    if (b > a) return 0;

    int res = 1;
    for (int i = 1, j = a; i <= b; i ++, j -- )
    {
        res = (LL)res * j % p;
        res = (LL)res * qmi(i, p - 2, p) % p;
    }
    return res;
}


int lucas(LL a, LL b, int p)
{
    if (a < p && b < p) return C(a, b, p);
    return (LL)C(a % p, b % p, p) * lucas(a / p, b / p, p) % p;
}


signed main()
{
    int n;
    cin >> n;
    vector<int> s(n+10);
    s[0]=1;
    for(int i=1;i<=n;i++) s[i]=s[i-1]*i%mod;
    int sum=0;
    for(int x=1;x<=n;x++){
        sum=(sum+lucas(n-x,x-1,mod)*s[n-x]%mod*s[x-1]%mod)%mod;
        //cout<<n-x<<' '<<x-1<<' '<<s[n-x]<<' '<<lucas(n-x,x-1,mod)<<endl;
    }
    cout<<(sum+mod)%mod<<endl;
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 3612kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 0ms
memory: 3508kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 0ms
memory: 3596kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 3608kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 0ms
memory: 3500kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 0ms
memory: 3612kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 0ms
memory: 3548kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 0ms
memory: 3560kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 0ms
memory: 3612kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 1ms
memory: 3784kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 3540kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 4ms
memory: 3804kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 14ms
memory: 3616kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: -100
Time Limit Exceeded

input:

1361956

output:


result: