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
#399352#6736. Alice and BobKidding_MaAC ✓118ms159960kbC++141.1kb2024-04-26 11:01:592024-04-26 11:02:00

Judging History

你现在查看的是最新测评结果

  • [2024-04-26 11:02:00]
  • 评测
  • 测评结果:AC
  • 用时:118ms
  • 内存:159960kb
  • [2024-04-26 11:01:59]
  • 提交

answer

#include "bits/stdc++.h"

using namespace std;
using i64 = long long;

constexpr int P = 998244353;
i64 *fac, *ifac;

i64 power(i64 a, i64 b, int p = P) {
    i64 res = 1;
    for (; b; b >>= 1, a = a * a % p) {
        if (b & 1) {
            res = res * a % p;
        }
    }
    return res;
}
   
i64 inv(i64 x) {
    return power(x, P - 2, P);
}
  
void init(int N) {
    fac = new i64 [N + 1];
    ifac = new i64 [N + 1];
    fac[0] = 1;
    for (int i = 1; i <= N; i++) {
        fac[i] = fac[i - 1] * i % P;
    }
    ifac[N] = inv(fac[N]);
    for (int i = N - 1; i >= 0; i--) {
        ifac[i] = ifac[i + 1] * (i + 1) % P;
    }
}
  
i64 C(int n, int m) {
    if (m < 0 || m > n || n < 0) {
        return 0;
    }
    return fac[n] * ifac[m] % P * ifac[n - m] % P;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    init(1E7);

    int n;
    cin >> n;
    i64 ans = 0;
    for (int i = 1; i <= (n + 1) / 2; i++) {
        ans = (ans + C(n - i, i - 1) * fac[n - i] % P * fac[i - 1]) % P;
    }
    cout << ans << '\n';

    return 0;
}

詳細信息

Test #1:

score: 100
Accepted
time: 84ms
memory: 159908kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 85ms
memory: 159832kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 77ms
memory: 159836kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 86ms
memory: 159828kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 81ms
memory: 159872kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 84ms
memory: 159956kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 84ms
memory: 159892kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 80ms
memory: 159836kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 92ms
memory: 159956kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 85ms
memory: 159888kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 82ms
memory: 159960kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 92ms
memory: 159880kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 91ms
memory: 159836kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 91ms
memory: 159872kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 107ms
memory: 159896kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 108ms
memory: 159956kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 99ms
memory: 159900kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 101ms
memory: 159896kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 108ms
memory: 159956kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 75ms
memory: 159896kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 110ms
memory: 159880kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 110ms
memory: 159872kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 118ms
memory: 159904kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"