QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#476622 | #6736. Alice and Bob | yudiao_vicky | RE | 1ms | 5736kb | C++11 | 815b | 2024-07-13 20:30:56 | 2024-07-13 20:30:56 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod=998244353;
int fac[1000005],inv[10000005];
int ksm(int a,int b,int p){
int res=1;
while(b){
if(b&1)res=res*a%p;
a=a*a%p;
b>>=1;
}
return res;
}
void solve()
{
int n;
cin>>n;
fac[0]=1;
for (int i=1;i<=n;i++){
fac[i]=fac[i-1]*i%mod;
}
inv[n]=ksm(fac[n],mod-2,mod);
for (int i=n-1;i>=0;i--){
inv[i]=inv[i+1]*(i+1)%mod;
}
int res=0;
for(int i=1;i<=(n+1)/2;++i){
(res+=fac[n-i]*fac[n-i]%mod*inv[n-2*i+1]%mod)%=mod;
}
cout<<res<<endl;
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t=1;
while(t--){
solve();
}
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 5676kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5688kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 5600kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 5600kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 5624kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 5728kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 5736kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 5604kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 5628kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 5664kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 5688kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 1ms
memory: 5680kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 5692kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: -100
Runtime Error
input:
1361956