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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 |
---|---|---|---|---|---|---|---|---|---|
#409717 | #6736. Alice and Bob | asoulcoming# | RE | 24ms | 8456kb | C++20 | 1.0kb | 2024-05-12 16:35:41 | 2024-05-12 16:35:42 |
Judging History
answer
#include<bits/stdc++.h>
#define int long long
#define lowbit(x) x&(-x)
#define endl '\n'
using namespace std;
const int N=2e5+10;
const int mod=998244353;
typedef pair<int,int>PII;
int a[N],f[N],fact[N],infact[N];
int qmi(int a, int k, int p) // 快速幂模板
{
int res = 1;
while (k)
{
if (k & 1) res =res * a % p;
a = a * a % p;
k >>= 1;
}
return res;
}
int C(int n,int m){
if(n<0||m<0)return 0;
if(m>n)return 0;
return ((fact[n]%mod*infact[m])%mod*infact[n-m]%mod)%mod;
}
void init()
{
fact[0] = infact[0] = 1;
for (int i = 1; i <N; i ++ )
{
fact[i] = fact[i - 1] * i % mod;
infact[i] = infact[i - 1] * qmi(i, mod - 2, mod) % mod;
}
}
void solve()
{
int n;
cin>>n;
int ans=fact[n-1];
for(int i=2;i<=n;i++)
{
ans=(ans+C(n-i,i-1)*fact[i-1]%mod*fact[n-i]%mod)%mod;
}
cout<<ans<<endl;
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t=1;
init();
// cin>>t;
while(t--)solve();
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 24ms
memory: 8456kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 23ms
memory: 8112kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 19ms
memory: 8340kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 24ms
memory: 8144kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 19ms
memory: 7112kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 19ms
memory: 7988kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 23ms
memory: 8348kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 23ms
memory: 7808kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 23ms
memory: 8260kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 19ms
memory: 6960kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 23ms
memory: 7068kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 23ms
memory: 7088kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 24ms
memory: 7640kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: -100
Runtime Error
input:
1361956