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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
#175465#6736. Alice and Bob_QWS_AC ✓184ms238096kbC++14767b2023-09-10 18:22:052023-09-10 18:22:05

Judging History

你现在查看的是最新测评结果

  • [2023-09-10 18:22:05]
  • 评测
  • 测评结果:AC
  • 用时:184ms
  • 内存:238096kb
  • [2023-09-10 18:22:05]
  • 提交

answer

#include <bits/stdc++.h>
#define ios ios::sync_with_stdio(0),cin.tie(0)
#define int long long

using namespace std;

const int N=1e7+10;

int inv[N];
int fc[N],fc_inv[N];

void init_tot(int n,int mod) {
	inv[1]=fc[0]=fc[1]=fc_inv[0]=fc_inv[1]=1;
	for(int i=2; i<=n; i++) {
		inv[i]=(mod-mod/i)*inv[mod%i]%mod;
		fc[i]=fc[i-1]*i%mod;
		fc_inv[i]=inv[i]*fc_inv[i-1]%mod;
	}
}

signed main(){
	ios;
	int n;
	cin>>n;
	int mod=998244353;
	init_tot(n+1,mod);
	int res=0;
	auto C=[&](int m,int n){
		return 1ll*fc[m]*fc_inv[n]%mod*fc_inv[m-n]%mod;
	};
	for(int x=1;x<=n;x++){
		if(x-1>n-x)break;
//		cout<<x<<"\n";
		
		res=(res+1ll*C(n-x,x-1)*fc[n-x]%mod*fc[x-1]%mod)%mod;
//		res=(res+C(n-x,x-1)*fc[n-x]);
	}
		
	cout<<res<<"\n";
}

詳細信息

Test #1:

score: 100
Accepted
time: 1ms
memory: 7764kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 2ms
memory: 7744kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 7768kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 7764kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 7756kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 1ms
memory: 7748kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 7808kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 1ms
memory: 7768kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 0ms
memory: 7696kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 1ms
memory: 7768kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 1ms
memory: 7820kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 1ms
memory: 7752kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 1ms
memory: 7680kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 12ms
memory: 40380kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 112ms
memory: 187580kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 123ms
memory: 199288kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 97ms
memory: 151300kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 65ms
memory: 89872kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 123ms
memory: 172960kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 46ms
memory: 76492kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 168ms
memory: 238048kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 184ms
memory: 238096kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 161ms
memory: 237960kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"