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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#133766#6736. Alice and BobbigJAC ✓121ms81764kbC++201.8kb2023-08-02 13:56:402023-08-02 13:56:44

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-08-02 13:56:44]
  • 评测
  • 测评结果:AC
  • 用时:121ms
  • 内存:81764kb
  • [2023-08-02 13:56:40]
  • 提交

answer

#include <bits/stdc++.h>

template<typename T, std::size_t N> std::istream& operator>>(std::istream& is, std::array<T, N>& v) { for (auto& i : v) is >> i; return is; }
template<typename T, std::size_t N> std::ostream& operator<<(std::ostream& os, std::array<T, N>& v) { for (auto& i : v) os << i << " "; return os; }
template<typename T> std::istream& operator>>(std::istream& is, std::vector<T>& v) { for (auto& i : v) is >> i; return is; }
template<typename T> std::ostream& operator<<(std::ostream& os, std::vector<T>& v) { for (auto& i : v) os << i << " "; return os; }
template<typename T> auto dbug(const std::initializer_list<T>& a) { std::cerr << "dbug: "; for (auto& i : a) std::cerr << i << " "; std::cerr << std::endl; }

using i64 = long long;

constexpr int N = 1e7;
constexpr int P = 998244353;

bool is_init;
int fac[N + 1], invfac[N + 1];

constexpr i64 power(i64 a, i64 b) {
    i64 res = 1;
    for (; b; b /= 2, a = a * a % P) {
        if (b % 2) {
            res = res * a % P;
        }
    }
    return res;
}

void init() {
    fac[0] = 1;
    for (int i = 1; i <= N; i++) {
        fac[i] = 1LL * fac[i - 1] * i % P;
    }
    invfac[N] = power(fac[N], P - 2);
    for (int i = N; i >= 1; i--) {
        invfac[i - 1] = 1LL * invfac[i] * i % P;
    }
    is_init = true;
}

int binom(int n, int m) {
    if (!is_init) init();
    if (n < m || m < 0) {
        return 0;
    }
    return 1LL * fac[n] * invfac[m] % P * invfac[n - m] % P;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    init();

    int n;
    std::cin >> n;

    int ans = fac[n - 1];
    for (int i = 2; i <= n; i++) {
        ans = (1LL * ans + 1LL * fac[n - i] % P * binom(n - i, i - 1) % P * fac[i - 1] % P) % P;
    }

    std::cout << ans << "\n";

    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 72ms
memory: 81760kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 89ms
memory: 81652kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 80ms
memory: 81500kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 80ms
memory: 81536kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 83ms
memory: 81656kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 84ms
memory: 81600kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 80ms
memory: 81764kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 81ms
memory: 81656kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 77ms
memory: 81600kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 72ms
memory: 81536kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 81ms
memory: 81508kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 84ms
memory: 81544kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 81ms
memory: 81548kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 90ms
memory: 81760kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 112ms
memory: 81700kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 109ms
memory: 81596kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 110ms
memory: 81588kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 101ms
memory: 81704kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 116ms
memory: 81588kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 96ms
memory: 81612kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 121ms
memory: 81544kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 121ms
memory: 81588kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 120ms
memory: 81760kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"