QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#407290#6736. Alice and Bobtjf4#AC ✓118ms159916kbC++201.1kb2024-05-08 14:24:092024-05-08 14:24:18

Judging History

你现在查看的是最新测评结果

  • [2024-05-08 14:24:18]
  • 评测
  • 测评结果:AC
  • 用时:118ms
  • 内存:159916kb
  • [2024-05-08 14:24:09]
  • 提交

answer

#include<bits/stdc++.h>
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
using namespace std;
typedef double db;
typedef long long ll;
typedef pair<ll,ll> pii;
typedef vector<pii> vii;
typedef vector<ll> vi;
typedef vector<string> vs;
typedef vector<char> vc;
const int inf=0x3f;
const int N=1e7+10;
const int mod=998244353;
ll q[N],inv[N];
ll pow_mod(ll a,ll b) {
	ll res=1;
	while(b) {
		if(b&1) res=(res*a)%mod;
		b>>=1;
		a=(a*a)%mod;
	}
	return res;
}
void init() {
	q[0]=1;
	for(int i=1;i<N;i++) q[i]=q[i-1]*i%mod;
	inv[N-1]=pow_mod(q[N-1],mod-2);
	for(int i=N-1;i>=1;i--) inv[i-1]=inv[i]*i%mod;
}
ll C(ll n,ll m) {
	if(n<m||n<0||m<0) return 0;
    if(n==m||m==0) return 1;
	return q[n]*inv[m]%mod*inv[n-m]%mod;
}
ll n;
int main() {
	init();
	cin>>n;
	ll res=0;
	for(int i=1;i<=n;i++) {//以i为第一个 
		ll x=i-1;//后面有几个位置 
		ll y=n-i;//比i大的选x个填入 
		if(y<x) break;
		ll su=C(y,x)*q[x]%mod*q[n-i]%mod;
		res+=su;
		if(res>=mod) res-=mod;
	}
	cout<<res%mod;
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 81ms
memory: 159748kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

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

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 92ms
memory: 159824kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 86ms
memory: 159804kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 72ms
memory: 159916kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 89ms
memory: 159808kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 72ms
memory: 159912kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 82ms
memory: 159820kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 80ms
memory: 159820kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 81ms
memory: 159880kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 80ms
memory: 159892kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 89ms
memory: 159736kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 70ms
memory: 159824kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 92ms
memory: 159792kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 107ms
memory: 159864kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 100ms
memory: 159740kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 103ms
memory: 159828kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 92ms
memory: 159744kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 118ms
memory: 159844kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 90ms
memory: 159744kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: 0
Accepted
time: 117ms
memory: 159740kb

input:

9999998

output:

758172780

result:

ok 1 number(s): "758172780"

Test #22:

score: 0
Accepted
time: 114ms
memory: 159820kb

input:

9999999

output:

605195495

result:

ok 1 number(s): "605195495"

Test #23:

score: 0
Accepted
time: 106ms
memory: 159808kb

input:

10000000

output:

866813682

result:

ok 1 number(s): "866813682"