QOJ.ac
QOJ
| ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
|---|---|---|---|---|---|---|---|---|---|
| #402715 | #6736. Alice and Bob | altaires1# | AC ✓ | 129ms | 159884kb | C++14 | 727b | 2024-05-01 11:29:41 | 2024-05-01 11:29:41 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define int long long
const int p=998244353;
const int N=1e7+5;
int fact[N],infact[N];
int qmi(int m,int k)
{
int res=1%p,t=m;
while(k)
{
if(k&1)res=res*t%p;
t=t*t%p;
k>>=1;
}
return res;
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0),cout.tie(0);
int res=0;
int n;
cin>>n;
fact[0]=infact[0]=1;
for(int i=1;i<=N;i++)
{
fact[i]=fact[i-1]*i%p;
}
infact[N]=qmi(fact[N],p-2);
for(int i=N-1;i>=1;i--)
{
infact[i]=infact[i+1]*(i+1)%p;
}
for(int i=1;i<=n;i++)
{
if(n-i<i-1)continue;
res=(res+fact[n-i]*infact[i-1]%p*infact[n-i-i+1]%p*fact[i-1]%p*fact[n-i]%p)%p;
}
cout<<res<<'\n';
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 76ms
memory: 159680kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 78ms
memory: 159680kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 75ms
memory: 159880kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 93ms
memory: 159728kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 89ms
memory: 159788kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 94ms
memory: 159800kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 89ms
memory: 159832kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 83ms
memory: 159744kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 79ms
memory: 159804kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 86ms
memory: 159788kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 95ms
memory: 159884kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 95ms
memory: 159820kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 98ms
memory: 159748kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 88ms
memory: 159836kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 91ms
memory: 159728kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 129ms
memory: 159832kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 114ms
memory: 159788kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 107ms
memory: 159872kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 100ms
memory: 159804kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 100ms
memory: 159796kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 118ms
memory: 159804kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 117ms
memory: 159740kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 127ms
memory: 159808kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"