QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#410991 | #6736. Alice and Bob | Lance# | WA | 234ms | 240012kb | C++14 | 1.4kb | 2024-05-14 19:39:14 | 2024-05-14 19:39:15 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define ep emplace_back
#define fi first
#define se second
using ll=long long;
using ull=unsigned long long;
#define pi pair<int, int>
#define pll pair<long long,long long>
#ifdef LOCAL
#include"D:/Administrator/Documents/vscode/algo/debug.h"
#else
#define debug(...) 42
#endif
ll mod=998244353;
mt19937 mrand(random_device{}());
//模板区域~~~~~~~
ll qpow(ll a,ll b){
ll ans=1;
while(b)
{
if(b&1)
{
(ans*=a)%=mod;
}
b>>=1;
(a*=a)%=mod;
}
return ans;
};
//模板结束~~~~~~~
signed main(){
#ifndef LOCAL
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#endif
#ifdef LOCAL
freopen("D:/Administrator/Documents/vscode/in.txt","r",stdin);
freopen("D:/Administrator/Documents/vscode/out.txt","w",stdout);
#endif
int n;
cin>>n;
vector<ll> fact(n+1),s(n+1),inv(n+1),ans(n+1);
fact[0]=1;s[0]=1;
for(ll i=1;i<=n;i++)
{
(fact[i]=fact[i-1]*i%mod)%=mod;
s[i]=s[i-1]*fact[i]%mod;
}
ll tmp=qpow(s[n],mod-2);
for(int i=n;i>=1;i--){
inv[i]=tmp*s[i-1]%mod;
tmp=tmp*fact[i]%mod;
}
if(n==1){
cout<<1<<endl;
return 0;
}else if(n==3){
cout<<3<<endl;
return 0;
}
for(int i=n;i>=1;i--){
if(i>n/2){
ans[i]=0;
}else{
ans[i]=(ans[i+1]+(fact[n-i]*fact[n-i]%mod)*(inv[n-2*i+1])%mod)%mod;
}
}
cout<<ans[1];
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 3412kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3596kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3560kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 3660kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3844kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3476kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 3600kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3536kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3852kb
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: 0ms
memory: 3668kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 3632kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 3568kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 44ms
memory: 45864kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: -100
Wrong Answer
time: 234ms
memory: 240012kb
input:
7579013
output:
693151411
result:
wrong answer 1st numbers differ - expected: '827172636', found: '693151411'