QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#356299 | #6736. Alice and Bob | star_xiao# | TL | 976ms | 199600kb | C++23 | 1.0kb | 2024-03-17 17:23:50 | 2024-03-17 17:23:52 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
//int n;
#define int long long
const int mod=998244353;
const int N=1e7+10;
int sum[N];
int fac[N],infac[N];
int n;
int qmi(int a,int b)
{
int res=1ll;
while(b)
{
if(b&1) res=res*a%mod;
b>>=1;
a=a*a%mod;
}
return res%mod;
}
void init()
{
fac[0]=infac[0]=1ll;
for(int i=1;i<=n;i++)
{
fac[i]=fac[i-1]*i%mod;
infac[i]=infac[i-1]*qmi(i,mod-2)%mod;
}
}
int C(int a,int b)
{
return fac[b]*infac[a]%mod*infac[b-a]%mod;
}
void solve()
{
int ans=0;
scanf("%lld",&n);
sum[0]=1ll;
init();
//cout<<C(3,2);
for(int i=1;i<=n;i++)
{
//ans=ans*i%mod;
sum[i]=sum[i-1]*i%mod;
sum[i]=(sum[i]+mod)%mod;
}
//sum[0]=0;
ans=(sum[n-1]+mod)%mod;
for(int i=2;i<=(n+1)/2;i++)
{
ans=(ans+(C(i-1,n-i)%mod)*sum[i-1]%mod*sum[n-i]%mod+mod)%mod;
//cout<<ans<<'\n';
}
printf("%lld\n",(ans+mod)%mod);
}
signed main()
{
//ios::sync_with_stdio(false);
//cin.tie(0),cout.tie(0);
solve();
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 7928kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 7904kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 8052kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 7984kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 7940kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 7916kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 7912kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 7872kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 8060kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 8016kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 7868kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 7924kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 8016kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 156ms
memory: 40900kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 911ms
memory: 187128kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 976ms
memory: 199600kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 736ms
memory: 151536kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 429ms
memory: 89996kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 841ms
memory: 169816kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 349ms
memory: 76832kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: -100
Time Limit Exceeded
input:
9999998