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 |
---|---|---|---|---|---|---|---|---|---|
#407972 | #6736. Alice and Bob | zhoujiu# | AC ✓ | 140ms | 159908kb | C++14 | 1.3kb | 2024-05-09 15:29:55 | 2024-05-09 15:29:57 |
Judging History
answer
#include<bits/stdc++.h>
#define int long long
using namespace std;
const int mod=998244353,N=1e7+10;
int n,m;
int fact[N],infact[N];
int qmi(int a,int k)
{
int res=1;
while(k)
{
if(k&1) res=res*a%mod;
k>>=1;
a=a*a%mod;
}
return res;
}
int C(int a,int b)
{
if(b>a) return 0;
return fact[a]*infact[b]%mod*infact[a-b]%mod;
}
void solve()
{
cin>>n;
// vector<int>a(n);
// for(int i=0;i<n;i++){
// a[i] = i+1;
// }
// vector<int>t = a;
// int c = 0;
// do{
// int mn = a[0];
// for(int i=0;i<a[0];i++){
// mn = min(mn,a[i]);
// }
// if(mn==a[0]){
// c++;
// }
// next_permutation(a.begin(),a.end());
// }while(a != t);
// cout<<c<<'\n';
fact[0]=infact[0]=1;
for(int i=1;i<=n;i++)
{
fact[i]=fact[i-1]*i%mod;
// cout<<fact[i]<<' '<<infact[i]<<'\n';
}
infact[n] = qmi(fact[n], mod - 2);
for(int i = n -1; i >= 1; i--)
{
infact[i] = infact[i + 1] * (i + 1) % mod;
}
// cout<<C(4,2)<<'\n';
int res=0;
for(int i=1;i<=n;i++)
{
res=(res+C(n-i,i-1)*fact[i-1]%mod*fact[n-i]%mod)%mod;
}
// res=((fact[n]-res)%mod+mod)%mod;
cout<<res<<'\n';
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
int t=1;
// cin>>t;
while(t--)
solve();
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 1ms
memory: 5572kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 3628kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3584kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 3588kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3572kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3624kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 3584kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3632kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3664kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 3660kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 3624kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 3676kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 3632kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 15ms
memory: 24864kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 104ms
memory: 122016kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 111ms
memory: 130856kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 76ms
memory: 101432kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 48ms
memory: 59472kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 99ms
memory: 113456kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 39ms
memory: 49648kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 128ms
memory: 159908kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 140ms
memory: 159808kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 120ms
memory: 159848kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"