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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
#383931#6736. Alice and BobGordenGhost#WA 152ms142344kbC++171.3kb2024-04-09 18:58:282024-04-09 18:58:30

Judging History

你现在查看的是最新测评结果

  • [2024-04-09 18:58:30]
  • 评测
  • 测评结果:WA
  • 用时:152ms
  • 内存:142344kb
  • [2024-04-09 18:58:28]
  • 提交

answer

#include"bits/stdc++.h"
#define endl '\n'
using ll=long long;
using namespace std;
constexpr int N=10000000+5,mod=998244353;
ll fact[N],inv[N];
ll qpow(ll a,ll b,ll p){
	a%=p;
	ll ans=1%p;
	for(;b;b>>=1){
		if(b&1)
			ans=ans*a%p;
		a=a*a%p;
	}
	return ans;
}
ll inverse(ll a,ll m){
	return qpow(fact[a],m-2,m);
//	if(a==0)
//		return qpow(fact[0],m-2,m);
//	return inv[a];
}
ll C(ll n,ll r,ll m){
	if(r>n)
		return 0;
	return ((fact[n]*inverse(r,m))%m*inverse(n-r,m)%m);
}
ll Lucas(ll n,ll r,ll m){
	if(r==0)
		return 1;
	return C(n%m,r%m,m)*Lucas(n/m,r/m,m)%m;
}
void init(ll n,ll p){
	fact[0]=1;
	for(int i=1;i<=n;i++)
		fact[i]=(fact[i-1]*i)%p;
	inv[1]=1;
	for(int i=2;i<=N-5;i++){
		inv[i]=(mod-mod/i)*inv[mod%i]%mod;
	}
}
void slove(){
	int n;
	cin>>n;
	init(n,mod);
	ll ans=0;
	if(n==1){
		cout<<1<<endl;
		return;
	}
	ll tot=1;
	int j=n-1;
	for(int i=1;i<=n/2;i++){
//		ans+= Lucas(n-i,i-1,mod)*fact[i-1]%mod  *fact[n-i]%mod;
//		cout<<Lucas(n-i,i-1,mod)*fact[i-1]%mod  *fact[n-i]%mod<<endl;
//		ans%=mod;
		for(;j>=n-2*i+2;j--){
			tot*=j;
			tot%=mod;
		}
//		cout<<tot<<endl;
		ans+=tot*fact[n-i];
		ans%=mod;
		tot=tot*inv[n-i];
		tot%=mod;
	}
	cout<<ans<<endl;
}
signed main(){
	cin.tie(nullptr)->sync_with_stdio(0);
	int _=1;
//	cin>>_;
	while(_--){
		slove();
	}
	return 0;
}

详细

Test #1:

score: 100
Accepted
time: 54ms
memory: 83308kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 59ms
memory: 82780kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 49ms
memory: 83752kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 46ms
memory: 81748kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 62ms
memory: 82364kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 51ms
memory: 81848kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 60ms
memory: 82196kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 59ms
memory: 83160kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 54ms
memory: 81752kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 64ms
memory: 83596kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 51ms
memory: 82624kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 63ms
memory: 81856kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 52ms
memory: 82920kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 60ms
memory: 94296kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: -100
Wrong Answer
time: 152ms
memory: 142344kb

input:

7579013

output:

693151411

result:

wrong answer 1st numbers differ - expected: '827172636', found: '693151411'