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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#360792#6736. Alice and Bob1366397866TL 905ms130888kbC++141.5kb2024-03-22 08:58:152024-03-22 08:58:15

Judging History

你现在查看的是最新测评结果

  • [2024-03-22 08:58:15]
  • 评测
  • 测评结果:TL
  • 用时:905ms
  • 内存:130888kb
  • [2024-03-22 08:58:15]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;
#define endl "\n"
#define PII pair<int,int>
#define int long long
const int N=1e7+10;
const int INF=1e18;
namespace DEBUG {
template <typename T>
void _debug(const char* format, T t) {
  cerr << format << '=' << t << endl;
}
template <class First, class... Rest>
void _debug(const char* format, First first, Rest... rest) {
  while (*format != ',') cerr << *format++;
  cerr << '=' << first << ",";
  _debug(format + 1, rest...);
}
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& V) {
  os << "[ ";
  for (const auto& vv : V) os << vv << ", ";
  os << "]";
  return os;
}
#define debug(...) _debug(#__VA_ARGS__, __VA_ARGS__)
}  // namespace DEBUG

using namespace DEBUG;
const int mod=998244353;
int jc[N],invjc[N];
int n;
int q_pow(int a, int k, int p) {
	int res = 1;
	while (k) {
		if (k & 1) res = res * a % p;
		a = a * a % p;
		k >>= 1;
	}
	return res;
}
void init()
{
    jc[0]=1;
    invjc[0]=1;
    for(int i=1;i<=n;i++)
    {
        jc[i]=jc[i-1]*i%mod;
        invjc[i]=invjc[i-1]*q_pow(i,mod-2,mod)%mod;
    }
}
int C(int a,int b)
{
    if(a<b)return 0;
    return jc[a]*invjc[b]%mod*invjc[a-b]%mod;
}
void solve()
{
	cin>>n;
	init();
	int sum=0;
	for(int i=1;i<=n;i++)
	{
		if(n-i<i-1)break;
		sum=(sum+jc[n-i]*jc[n-i]%mod*invjc[n-2*i+1]%mod)%mod;
	}
	cout<<sum%mod<<endl;
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	int T=1;
//	cin>>T;
	while(T--)solve();
	return 0; 
} 

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 3624kb

input:

1

output:

1

result:

ok 1 number(s): "1"

Test #2:

score: 0
Accepted
time: 0ms
memory: 3664kb

input:

2

output:

1

result:

ok 1 number(s): "1"

Test #3:

score: 0
Accepted
time: 1ms
memory: 3612kb

input:

10

output:

997920

result:

ok 1 number(s): "997920"

Test #4:

score: 0
Accepted
time: 1ms
memory: 3612kb

input:

100

output:

188898954

result:

ok 1 number(s): "188898954"

Test #5:

score: 0
Accepted
time: 1ms
memory: 3572kb

input:

4

output:

10

result:

ok 1 number(s): "10"

Test #6:

score: 0
Accepted
time: 0ms
memory: 3652kb

input:

8

output:

12336

result:

ok 1 number(s): "12336"

Test #7:

score: 0
Accepted
time: 1ms
memory: 3660kb

input:

16

output:

373118483

result:

ok 1 number(s): "373118483"

Test #8:

score: 0
Accepted
time: 0ms
memory: 3676kb

input:

32

output:

314585464

result:

ok 1 number(s): "314585464"

Test #9:

score: 0
Accepted
time: 1ms
memory: 3624kb

input:

64

output:

627827331

result:

ok 1 number(s): "627827331"

Test #10:

score: 0
Accepted
time: 0ms
memory: 3548kb

input:

128

output:

828497685

result:

ok 1 number(s): "828497685"

Test #11:

score: 0
Accepted
time: 0ms
memory: 3664kb

input:

256

output:

65697890

result:

ok 1 number(s): "65697890"

Test #12:

score: 0
Accepted
time: 0ms
memory: 3624kb

input:

512

output:

854187619

result:

ok 1 number(s): "854187619"

Test #13:

score: 0
Accepted
time: 1ms
memory: 3628kb

input:

1024

output:

513823539

result:

ok 1 number(s): "513823539"

Test #14:

score: 0
Accepted
time: 157ms
memory: 24844kb

input:

1361956

output:

617368199

result:

ok 1 number(s): "617368199"

Test #15:

score: 0
Accepted
time: 820ms
memory: 122084kb

input:

7579013

output:

827172636

result:

ok 1 number(s): "827172636"

Test #16:

score: 0
Accepted
time: 905ms
memory: 130888kb

input:

8145517

output:

710624331

result:

ok 1 number(s): "710624331"

Test #17:

score: 0
Accepted
time: 660ms
memory: 99620kb

input:

6140463

output:

707600568

result:

ok 1 number(s): "707600568"

Test #18:

score: 0
Accepted
time: 392ms
memory: 58580kb

input:

3515281

output:

698302413

result:

ok 1 number(s): "698302413"

Test #19:

score: 0
Accepted
time: 769ms
memory: 112516kb

input:

6969586

output:

69470392

result:

ok 1 number(s): "69470392"

Test #20:

score: 0
Accepted
time: 312ms
memory: 48748kb

input:

2888636

output:

433579983

result:

ok 1 number(s): "433579983"

Test #21:

score: -100
Time Limit Exceeded

input:

9999998

output:

758172780

result: