QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#183574 | #6736. Alice and Bob | xz1195160770# | AC ✓ | 199ms | 238048kb | C++20 | 1012b | 2023-09-19 17:45:43 | 2023-09-19 17:45:43 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
using i64=long long;
using ll=long long;
const int N=1e7+10,mod=998244353;
int n;
ll fac[N],infac[N],inv[N];
ll qpow(ll a,ll b,ll p){
ll res=1;
while(b){
if(b&1) res=res*a%mod;
a=a*a%mod;
b>>=1;
}
return res;
}
void init(int n=N-1){
fac[0]=1;
for(int i=1;i<=n;i++) fac[i]=fac[i-1]*i%mod;
infac[n-1]=qpow(fac[n-1],mod-2,mod);
for(int i=n-2;i>=0;i--)
infac[i]=infac[i+1]*(i+1)%mod;
inv[0]=inv[1]=1;
for(int i=2;i<=n;i++) inv[i]=(mod-mod/i*inv[mod%i]%mod)%mod;
}
ll C(ll a,ll b){
if(a<b) return 0;
return fac[a]*infac[b]%mod*infac[a-b]%mod;
}
void solve(){
cin>>n;
ll ans=0;
for(int i=1;i<=n;i++){
ans+=C(n-i,i-1)*fac[n-i]%mod*fac[i-1]%mod;
ans%=mod;
}
cout<<ans<<endl;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0),cout.tie(0);
int t=1;
init();
//cin>>t;
while(t--) solve();
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 131ms
memory: 238020kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 182ms
memory: 238048kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 179ms
memory: 237960kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 178ms
memory: 237960kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 125ms
memory: 238024kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 155ms
memory: 238012kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 185ms
memory: 237956kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 178ms
memory: 237960kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 148ms
memory: 238016kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 178ms
memory: 238028kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 179ms
memory: 238028kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 148ms
memory: 238020kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 104ms
memory: 237948kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 146ms
memory: 238020kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 180ms
memory: 237952kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 197ms
memory: 237992kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 199ms
memory: 238024kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 146ms
memory: 237996kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 164ms
memory: 238016kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 157ms
memory: 238024kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 185ms
memory: 238032kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 180ms
memory: 238024kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 136ms
memory: 237980kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"