QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#413276 | #6736. Alice and Bob | gaotianyu# | WA | 881ms | 126052kb | C++14 | 1.1kb | 2024-05-17 10:54:57 | 2024-05-17 10:54:59 |
Judging History
answer
#include <bits/stdc++.h>
#define int long long
#define endl "\n"
using namespace std;
typedef pair<int, int> PII;
const double epx = 1e-4;
const int mod = 998244353;
const int N = 1e7 + 10;
vector<int> x;
int n, fac[N], inv[N];
int qmi(int a, int b)
{
int res = 1;
while (b)
{
if (b & 1) res = (res * a) % mod;
a = (a * a) % mod;
b >>= 1;
}
return res % mod;
}
void init() {
fac[0] = 1;
for (int i = 1; i <= n; i++) fac[i] = (fac[i - 1] * i) % mod;
for (int i = 1; i <= n; i++) inv[i] = qmi(fac[i], mod - 2);
}
int C(int n, int m)
{
if (m > n) return 0;
return ((fac[n] * inv[m]) % mod) * inv[n - m] % mod;
}
void solve()
{
cin >> n;
init();
int ans = fac[n - 1];
for (int i = 2; i <= n; i++)
{
if (n - i < i - 1) continue;
ans = (ans + (C(n - i, i - 1) * fac[i - 1] % mod) * fac[n - i]) % mod;
}
cout << (ans + mod) % mod << endl;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int tt = 1;
// cin>>tt;
while (tt--) solve();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 1ms
memory: 5668kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5584kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 5640kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 5592kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 5560kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 5664kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 5716kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 5520kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 1ms
memory: 5484kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 5624kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 5480kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 1ms
memory: 5592kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 5492kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 150ms
memory: 27000kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: -100
Wrong Answer
time: 881ms
memory: 126052kb
input:
7579013
output:
693151411
result:
wrong answer 1st numbers differ - expected: '827172636', found: '693151411'