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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
#403578#6736. Alice and Bobccsu_zx#AC ✓148ms159956kbC++141.0kb2024-05-02 15:09:262024-05-02 15:09:27

Judging History

你现在查看的是最新测评结果

  • [2024-05-02 15:09:27]
  • 评测
  • 测评结果:AC
  • 用时:148ms
  • 内存:159956kb
  • [2024-05-02 15:09:26]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;

#define ll long long
const int mod = 998244353;
const int N = 1e7+10;
ll fac[N], invfac[N];

ll ksm(ll A, ll B, ll p) {
	ll res = 1;
	while (B) {
		if (B&1) {
			res *= A;
			res %= p;
		}
		B /= 2;
		A *= A;
		A %= p;
	}
	return res;
} 

void init() {
	ll i, j;
	fac[0] = fac[1] = 1;
	invfac[0] = invfac[1] = 1;
	for (i = 1; i < N; i++) {
		fac[i] = fac[i-1] * i % mod;
	}
	invfac[N-1] = ksm(fac[N-1], mod-2, mod);
	for (i = N-1; i >= 2; i--) {
		invfac[i-1] = invfac[i] * i % mod;
	}
}

ll C(int n, int m) {
	if (n < m) return 0;
	return fac[n] * invfac[m] % mod * invfac[n-m] % mod;
}

ll A(int n) {
	return fac[n];
}

void solve() {
	int n, i, j;
	ll ans = 0;
	cin>>n;
	for (i = 1; i <= n; i++) {
		ans += C(n-i, i-1) * A(i-1) % mod * A(n-i) % mod;
		ans %= mod;
	}
	cout<<ans<<'\n';
}

// 1 1 3 

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	init();
	int T = 1;
//	cin>>T;
	while (T--) {
		solve();
	}
	return 0;
}

详细

Test #1:

score: 100
Accepted
time: 74ms
memory: 159952kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 73ms
memory: 159908kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 83ms
memory: 159956kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 84ms
memory: 159904kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 87ms
memory: 159952kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 89ms
memory: 159820kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 76ms
memory: 159816kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 77ms
memory: 159932kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 109ms
memory: 159940kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 90ms
memory: 159824kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 73ms
memory: 159888kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 81ms
memory: 159884kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 76ms
memory: 159904kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 104ms
memory: 159816kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 129ms
memory: 159864kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 148ms
memory: 159860kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 114ms
memory: 159884kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 91ms
memory: 159908kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 96ms
memory: 159880kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 72ms
memory: 159812kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 132ms
memory: 159888kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 138ms
memory: 159912kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 137ms
memory: 159880kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"