QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#364560 | #6736. Alice and Bob | Atmizz# | TL | 14ms | 3804kb | C++20 | 1.0kb | 2024-03-24 15:17:52 | 2024-03-24 15:17:52 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
typedef long long LL;
#define int long long
int qmi(int a, int k, int p)
{
int res = 1;
while (k)
{
if (k & 1) res = (LL)res * a % p;
a = (LL)a * a % p;
k >>= 1;
}
return res;
}
int C(int a, int b, int p)
{
if (b > a) return 0;
int res = 1;
for (int i = 1, j = a; i <= b; i ++, j -- )
{
res = (LL)res * j % p;
res = (LL)res * qmi(i, p - 2, p) % p;
}
return res;
}
int lucas(LL a, LL b, int p)
{
if (a < p && b < p) return C(a, b, p);
return (LL)C(a % p, b % p, p) * lucas(a / p, b / p, p) % p;
}
signed main()
{
int n;
cin >> n;
vector<int> s(n+10);
s[0]=1;
for(int i=1;i<=n;i++) s[i]=s[i-1]*i%mod;
int sum=0;
for(int x=1;x<=n;x++){
sum=(sum+lucas(n-x,x-1,mod)*s[n-x]%mod*s[x-1]%mod)%mod;
//cout<<n-x<<' '<<x-1<<' '<<s[n-x]<<' '<<lucas(n-x,x-1,mod)<<endl;
}
cout<<(sum+mod)%mod<<endl;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 3612kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3508kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3596kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 3608kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3500kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3612kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 3548kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3560kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3612kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 3784kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 3540kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 4ms
memory: 3804kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 14ms
memory: 3616kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: -100
Time Limit Exceeded
input:
1361956