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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#383635#6736. Alice and Bobqzhfx#AC ✓159ms81828kbC++232.9kb2024-04-09 16:07:532024-04-09 16:07:55

Judging History

你现在查看的是最新测评结果

  • [2024-04-09 16:07:55]
  • 评测
  • 测评结果:AC
  • 用时:159ms
  • 内存:81828kb
  • [2024-04-09 16:07:53]
  • 提交

answer

#pragma GCC optimize("Ofast,inline,unroll-loops,fast-math,no-stack-protector")
#include<bits/stdc++.h>
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
using namespace std;
using ll = int64_t;
using LL = long long;
using ull = uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using pii = pair<ll, ll>;
const int mod = 998244353;
const int N = 1e7 + 7;
const int maxn = 1e5 + 100;
template<const int T>
struct ModInt {
	const static int mod = T;
	int x;
	ModInt(int x = 0) : x(x % mod) {}
	ModInt(long long x) : x(int(x % mod)) {}
	int val() { return x; }
	ModInt operator + (const ModInt &a) const { int x0 = x + a.x; return ModInt(x0 < mod ? x0 : x0 - mod); }
	ModInt operator - (const ModInt &a) const { int x0 = x - a.x; return ModInt(x0 < 0 ? x0 + mod : x0); }
	ModInt operator * (const ModInt &a) const { return ModInt(1ll * x * a.x % mod); }
	ModInt operator / (const ModInt &a) const { return *this * a.inv(); }
	bool operator == (const ModInt &a) const { return x == a.x; };
	bool operator != (const ModInt &a) const { return x != a.x; };
	void operator += (const ModInt &a) { x += a.x; if (x >= mod) x -= mod; }
	void operator -= (const ModInt &a) { x -= a.x; if (x < 0) x += mod; }
	void operator *= (const ModInt &a) { x = 1ll * x * a.x % mod; }
	void operator /= (const ModInt &a) { *this = *this / a; }
	friend ModInt operator + (int y, const ModInt &a) { int x0 = y + a.x; return ModInt(x0 < mod ? x0 : x0 - mod); }
	friend ModInt operator - (int y, const ModInt &a) { int x0 = y - a.x; return ModInt(x0 < 0 ? x0 + mod : x0); }
	friend ModInt operator * (int y, const ModInt &a) { return ModInt(1ll * y * a.x % mod);}
	friend ModInt operator / (int y, const ModInt &a) { return ModInt(y) / a;}
	friend ostream &operator<<(ostream &os, const ModInt &a) { return os << a.x;}
	friend istream &operator>>(istream &is, ModInt &t) {return is >> t.x;}

	ModInt pow(int64_t n) const {
		ModInt res(1), mul(x);
		while (n) {
			if (n & 1) res *= mul;
			mul *= mul;
			n >>= 1;
		}
		return res;
	}

	ModInt inv() const {
		int a = x, b = mod, u = 1, v = 0;
		while (b) {
			int t = a / b;
			a -= t * b; swap(a, b);
			u -= t * v; swap(u, v);
		}
		if (u < 0) u += mod;
		return u;
	}

};
using mint = ModInt<mod>;
mint jc[N], ijc[N];
void init(int n) {
	jc[0] = 1;
	for (int i = 1; i <= n; i++) {
		jc[i] = jc[i - 1] * i;
	}
	ijc[n] = (mint)1 / jc[n];
	for(int i=n-1;i>=0;i--){
		ijc[i] = ijc[i + 1] * (i + 1);
	}
}
mint C(int n,int m){
	if(m > n)return 0;
	return jc[n]*ijc[m]*ijc[n - m];
}
void solve() {
	int n;
	cin >> n;
	init(n);
	mint ans = 0;
	for (int i = 1; i <= n; i++) {
		ans += C(n-i,i - 1) * jc[i - 1] * jc[n - i];
	}
	// ans = jc[n] - ans;
	cout << ans << '\n';
}
int main() {
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int _;
	_ = 1;
	// cin >> _;
	while (_--) {
		solve();
	}
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 7ms
memory: 81744kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 15ms
memory: 81756kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 27ms
memory: 81760kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 39ms
memory: 81664kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 8ms
memory: 81676kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 7ms
memory: 81748kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 31ms
memory: 81748kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 34ms
memory: 81696kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 34ms
memory: 81672kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 30ms
memory: 81732kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 23ms
memory: 81824kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 38ms
memory: 81752kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 23ms
memory: 81732kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 51ms
memory: 81756kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 102ms
memory: 81756kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 136ms
memory: 81732kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 102ms
memory: 81684kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 62ms
memory: 81828kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 117ms
memory: 81760kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 70ms
memory: 81696kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 151ms
memory: 81744kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 139ms
memory: 81764kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 159ms
memory: 81752kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"