QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#350631 | #6736. Alice and Bob | Albert711 | WA | 155ms | 3856kb | C++20 | 1.4kb | 2024-03-10 22:18:20 | 2024-03-10 22:18:20 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double db;
const int N = 10005 + 5;
const int mod = 998244353;
//#define int long long
using i64 = int64_t;
std::bitset<N> bt[N];
i64 fpow(i64 x, i64 r)
{
i64 result = 1;
while (r)
{
if (r & 1)result = result * x % mod;
r >>= 1;
x = x * x % mod;
}
return result;
}
namespace binom {
i64 fac[N], ifac[N];
int __ = []
{
fac[0] = 1;
for (int i = 1; i <= N - 5; i++)
fac[i] = fac[i - 1] * i % mod;
ifac[N - 5] = fpow(fac[N - 5], mod - 2);
for (int i = N - 5; i; i--)
ifac[i - 1] = ifac[i] * i % mod;
return 0;
}();
inline i64 C(int n, int m)
{
if (n < m || m < 0)return 0;
return fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}
inline i64 A(int n, int m)
{
if (n < m || m < 0)return 0;
return fac[n] * ifac[n - m] % mod;
}
}
using namespace binom;
void solve() {
ll n;
cin>>n;
ll ans=0;
ll tmp=1;
for(int i=1;i<=n-1;i++) tmp=tmp*i%mod;
ll tt=tmp;
for(int i=1;i<=n;i++){
ans=ans+A(n-i,i-1)*tt%mod;
ans%=mod;
tt=tt*fpow(n-i,mod-2)%mod;
}
cout<<ans<<'\n';
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
// cout << fixed << setprecision(1);
int T = 1;
// cin >> T;
while (T--) solve();
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 3724kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 3720kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 3764kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 3724kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 3724kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 3724kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 3792kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 3776kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 1ms
memory: 3764kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 1ms
memory: 3832kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 3856kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 3784kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 3816kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: -100
Wrong Answer
time: 155ms
memory: 3700kb
input:
1361956
output:
0
result:
wrong answer 1st numbers differ - expected: '617368199', found: '0'