QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#693780 | #6736. Alice and Bob | NULL_SF | TL | 937ms | 133352kb | C++23 | 778b | 2024-10-31 16:44:35 | 2024-10-31 16:44:36 |
Judging History
answer
#include <iostream>
#define int long long
using namespace std;
const int mod=998244353;
int pre[10000001],inv[10000001];
inline int quick_pow(int base,int index)
{
int ans=1,tmp=base%mod;
while(index){
if(index&1){
ans*=tmp;
ans%=mod;
}
tmp*=tmp;
tmp%=mod;
index>>=1;
}
return ans;
}
int get_inv(int x)
{
return quick_pow(x,mod-2);
}
int get_C(int down,int up)
{
return pre[down]*inv[up]%mod*inv[down-up]%mod;
}
signed main()
{
int n;
cin>>n;
pre[0]=inv[0]=1;
for(int i=1;i<=n;i++){
pre[i]=pre[i-1]*i%mod;
inv[i]=inv[i-1]*get_inv(i)%mod;
}
int ans=0;
for(int i=1;i<=(n+1)/2;i++){
ans+=pre[n-i]*pre[i-1]%mod*get_C(n-i,i-1)%mod;
ans%=mod;
}
cout<<ans;
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 5608kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5604kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 5684kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 5600kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 5732kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 5600kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 5668kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 5676kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 1ms
memory: 5680kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 5732kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 5684kb
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: 5564kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 160ms
memory: 27128kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 856ms
memory: 126188kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 937ms
memory: 133352kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 704ms
memory: 104732kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 403ms
memory: 61804kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 793ms
memory: 114252kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 330ms
memory: 51756kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: -100
Time Limit Exceeded
input:
9999998