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
#414427#6736. Alice and Bobfuyouyufeng#TL 331ms26956kbC++171.2kb2024-05-18 23:08:062024-05-18 23:08:07

Judging History

你现在查看的是最新测评结果

  • [2024-05-18 23:08:07]
  • 评测
  • 测评结果:TL
  • 用时:331ms
  • 内存:26956kb
  • [2024-05-18 23:08:06]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
#define int long long
const int N = 1e7 + 10, mod = 998244353;
long long f[N], infact[N];
LL qmi(LL a, LL k, LL p)
{
    LL res = 1;
    while (k)
    {
        if (k & 1)
            res = res * a % p;
        a = a * a % p;
        k >>= 1;
    }
    return res;
}
inline int c(int a, int b, int p) { return f[a] * infact[b] % p * infact[a - b] % p; }
void init_ass_two(int p, int n)
{
    f[0] = infact[0] = 1;
    // N的值是a和b的最大范围
    for (int i = 1; i <= n; i++)
    {
        f[i] = i * f[i - 1] % p;
        infact[i] = infact[i - 1] * qmi(i, p - 2, p) % p;
    }
} // cout<<c(a,b,p)<<'\n';
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    init_ass_two(mod, n);

    int mid = n / 2;
    if (n % 2 == 1)
        mid++;

    int res = 0;
    for (int i = 1; i <= mid; i++)
    {
        int x = 1;
        x = (x * c(n - i, i - 1, mod)) % mod;
        x = (x * f[i - 1]) % mod;
        x = (x * f[n - i]) % mod;

        res = (res + x) % mod;
    }

    cout << res ;

    return 0;
}

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 5688kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 0ms
memory: 5652kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 5592kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 5668kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 5652kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 5728kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 5616kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 0ms
memory: 5592kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 1ms
memory: 5664kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 1ms
memory: 5684kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 5676kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 5672kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 1ms
memory: 5608kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 331ms
memory: 26956kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: -100
Time Limit Exceeded

input:

7579013

output:


result: