QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#360792 | #6736. Alice and Bob | 1366397866 | TL | 905ms | 130888kb | C++14 | 1.5kb | 2024-03-22 08:58:15 | 2024-03-22 08:58:15 |
Judging History
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