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 |
|---|---|---|---|---|---|---|---|---|---|
| #661135 | #6736. Alice and Bob | ucup-team1769# | AC ✓ | 656ms | 3724kb | C++20 | 895b | 2024-10-20 14:52:36 | 2024-10-20 14:52:37 |
Judging History
answer
#include <bits/stdc++.h>
#define int long long
#define endl '\n'
#define IOS ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr)
using namespace std;
typedef pair<int, int> pii;
const int maxn = 1e6;
const int mod=998244353;
int mypow(int a,int b)
{
int ans=1;
for(;b;b>>=1)
{
if(b&1)
ans=ans*a%mod;
a=(a*a)%mod;
}
return ans%mod;
}
signed main()
{
IOS;
int N;
cin>>N;
if(N==1)
{
cout<<1<<endl;
return 0;
}
int a1=N-2,a2=1;
for(int i=1;i<=N-2;i++)
a2=a2*i%mod;
int ans=a2*(N-1)%mod;
for(int i=2;i<=N;i++)
{
if(N-i<i-1)break;
ans=(ans+a1*a2%mod)%mod;
int now=mypow(N-i,mod-2);
a1=a1*now%mod;
a1=(a1*(N-i-i+1)%mod)*(N-i-i)%mod;
a2=a2*now%mod;
}
cout<<ans%mod<<endl;
}
详细
Test #1:
score: 100
Accepted
time: 0ms
memory: 3724kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3684kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3664kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 3604kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3668kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3668kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 3636kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3672kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3668kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 3584kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 3608kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 3612kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 3664kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 90ms
memory: 3600kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 497ms
memory: 3616kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 534ms
memory: 3608kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 403ms
memory: 3688kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 227ms
memory: 3660kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 457ms
memory: 3680kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 190ms
memory: 3672kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 652ms
memory: 3680kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 656ms
memory: 3668kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 656ms
memory: 3668kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"