QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#379288 | #6736. Alice and Bob | Rykony | AC ✓ | 655ms | 81828kb | C++20 | 851b | 2024-04-06 16:56:24 | 2024-04-06 16:56:24 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod=998244353;
const int maxn=1e7+10;
int a[maxn];
int qpow(int a,int n)
{
int ans=1;
while (n){
if (n&1) ans=ans*a%mod;
a=a*a%mod;
n>>=1;
}
return ans;
}
void init()
{
a[0]=1;
for (int i=1;i<maxn;i++){
a[i]=a[i-1]*i%mod;
}
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
int _=1;
// cin>>_;
init();
while (_--){
int n;
cin>>n;
int ans=1;
for (int i=1;i<=n-1;i++) ans=ans*i%mod;
int d=n-2,mn=n-2;
for (int i=2;i<=n;i++){
if (i==2){
ans=(ans+a[n-i]*d)%mod;
}
else{
if (mn-2<=0) break;
// cout<<d<<'\n';
d=d*qpow(n-i+1,mod-2)%mod;
d=d*(mn-1)%mod*(mn-2)%mod;
mn-=2;
ans=(ans+d*a[n-i]%mod)%mod;
}
}
cout<<ans<<'\n';
}
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 52ms
memory: 81628kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 31ms
memory: 81620kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 48ms
memory: 81688kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 28ms
memory: 81736kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 43ms
memory: 81732kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 39ms
memory: 81732kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 48ms
memory: 81740kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 47ms
memory: 81728kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 45ms
memory: 81820kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 24ms
memory: 81732kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 39ms
memory: 81804kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 47ms
memory: 81732kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 33ms
memory: 81828kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 134ms
memory: 81744kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 501ms
memory: 81684kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 545ms
memory: 81768kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 411ms
memory: 81788kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 251ms
memory: 81736kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 461ms
memory: 81792kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 214ms
memory: 81744kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 629ms
memory: 81728kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 636ms
memory: 81792kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 655ms
memory: 81728kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"