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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#693633#6736. Alice and BobNULL_SFWA 1ms5732kbC++23758b2024-10-31 16:29:572024-10-31 16:29:59

Judging History

你现在查看的是最新测评结果

  • [2024-10-31 16:29:59]
  • 评测
  • 测评结果:WA
  • 用时:1ms
  • 内存:5732kb
  • [2024-10-31 16:29:57]
  • 提交

answer

#include <iostream>

#define int long long

using namespace std;

const int mod=998244353;

int pre[10000001],inv[10000001];

int quick_pow(int base,int index)
{
	int ans=1,tmp=base%mod;
	
	while(index){
		if(index&1){
			ans*=tmp;
			ans%=mod;
		}
		tmp*=tmp;
		tmp%=mod;
		index>>=1;
	}
	
	return ans;
}

int get_inv(int x)
{
	return quick_pow(x,mod-2);
}

int get_C(int down,int up)
{
	return pre[down]*inv[up]%mod*inv[down-up]%mod;
}

signed main()
{
	int n;
	cin>>n;
	
	pre[0]=inv[0]=1;
	for(int i=1;i<=n;i++){
		pre[i]=pre[i-1]*i%mod;
		inv[i]=inv[i-1]*get_inv(i)%mod;
	}
	
	int ans=0;
	for(int i=1;i<=(n+1)/2;i++){
		ans+=pre[n-i]*get_C(n-i,i-1)%mod;
		ans%=mod;
	}
	
	cout<<ans;
	
	return 0;
}

Details

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Test #1:

score: 100
Accepted
time: 1ms
memory: 5548kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 1ms
memory: 5732kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: -100
Wrong Answer
time: 1ms
memory: 5672kb

input:

10

output:

806280

result:

wrong answer 1st numbers differ - expected: '997920', found: '806280'