QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#213480 | #6736. Alice and Bob | YFOQ | WA | 968ms | 123300kb | C++11 | 1.8kb | 2023-10-14 14:26:31 | 2023-10-14 14:26:31 |
Judging History
answer
#include<bits/stdc++.h>
#define ll long long
#define x first
#define y second
#define IO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb(x) push_back(x)
#define endl '\n'
#define fix(x) cout << fixed << setprecision(x) ;
#pragma GCC optimize(2)
using namespace std;
typedef pair<int,int>PII;
typedef pair<double,double>PDD;
typedef pair<int,PII>PIP;
typedef pair<PII,int>PPI;
typedef vector<int>VI;
const int N =5e5+5;
const long long INF = 1e16;
int mod= 998244353;
ll a[10000001];
int kpow(int x,int n);
ll inv[10000001];
ll A(int n,int x){
return a[n]*inv[n-x]%mod;
}
inline void Solve(){
int n;
cin>>n;
a[0]=1;
inv[1]=1;
inv[0]=1;
a[1]=1;
ll t=kpow(2ll,mod-2);
for(int i=2;i<=n;i++){
a[i]=a[i-1]*i;
a[i]%=mod;
if(i%2==0){
inv[i]=inv[i/2]*t%mod;
}
else inv[i]=kpow(a[i],mod-2);
}
ll res =0;
for(int i=1;i<=n/2+1;++i){
res+=A((n-i),i-1)*(a[n-i]);
// cout<<res<<endl;
res%=mod;
}
cout<<res<<endl;
}
//1 0.75
signed main(){
IO
// fix(16);
int T=1;
// cin>>T;
for(int i=1;i<=T;i++){
Solve();
}
return 0;
}
/*
*/
int lowbit(int n)
{
return n&-n;
}
inline void read(int &x)
{
int f=0;x=0;char c=getchar();
while(c<'0'||c>'9')f|=c=='-',c=getchar();
while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar();
x=f?-x:x;
}
inline void print(long long x)
{
if(x<0){
putchar('-');
x=-x;
}
if(x>9) print(x/10);
putchar(x%10+'0');
}
//ofstream out("file.txt");
//ifstream in("file.txt");
inline int kpow(int x,int y){
if(y==0)return 1;
if(x==0)return 0;
long long res =1;
long long p=x;
for(int i=0;y>>i;++i){
if((y>>i)&1){
res*=p;
res%=mod;
}
p*=p;
p%=mod;
}
return res;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 5540kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 5480kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 5484kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 5388kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 5444kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 5600kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 5388kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 5644kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 1ms
memory: 5540kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 5444kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 5656kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 1ms
memory: 7588kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 5620kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 177ms
memory: 28308kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: -100
Wrong Answer
time: 968ms
memory: 123300kb
input:
7579013
output:
61181888
result:
wrong answer 1st numbers differ - expected: '827172636', found: '61181888'