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
#386753#6736. Alice and BobArnold_6#AC ✓168ms238100kbC++141000b2024-04-11 19:51:172024-04-11 19:51:17

Judging History

你现在查看的是最新测评结果

  • [2024-04-11 19:51:17]
  • 评测
  • 测评结果:AC
  • 用时:168ms
  • 内存:238100kb
  • [2024-04-11 19:51:17]
  • 提交

answer

# include <bits/stdc++.h>

using namespace std;
const int N = 1e7 + 10, mod = 998244353;
typedef long long LL;
int n;
LL fact[N], infact[N], inv[N];

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

void init()
{
    fact[0] = infact[0] = 1;
    inv[1] = 1;
    for(int i = 2; i < N; i ++) inv[i] = (LL)(mod - mod / i) * inv[mod % i] % mod;
    for(int i = 1; i < N; i ++)
    {
        fact[i] = (LL)fact[i - 1] * i % mod; 
        infact[i] = (LL)infact[i - 1] * inv[i] % mod;
    }

}

int A(int y, int x)
{
    return (LL)fact[x] * infact[x - y] % mod;
}

int main()
{
    init();
    cin >> n;
    LL res = 0;
    for(int i = 1; i <= (n + 1) / 2; i ++)
    {
        LL ans = (LL)A(i - 1, n - i) * fact[n - i] % mod;
        res = (res + ans) % mod;
    }
    cout << res << endl;
    //system("pause");
    return 0;
}

详细

Test #1:

score: 100
Accepted
time: 168ms
memory: 237884kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 124ms
memory: 238064kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 135ms
memory: 238008kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 130ms
memory: 237884kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 115ms
memory: 237884kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 119ms
memory: 238100kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 144ms
memory: 238008kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 134ms
memory: 237944kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 150ms
memory: 238008kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 127ms
memory: 238012kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 136ms
memory: 238096kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 150ms
memory: 237928kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 117ms
memory: 238020kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 116ms
memory: 238000kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 162ms
memory: 237888kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 139ms
memory: 237884kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 141ms
memory: 238008kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 143ms
memory: 238008kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 168ms
memory: 238024kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 155ms
memory: 238012kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 146ms
memory: 237936kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 163ms
memory: 238012kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 162ms
memory: 237964kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"