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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 |
|---|---|---|---|---|---|---|---|---|---|
| #411848 | #6736. Alice and Bob | xieweiwen# | TL | 192ms | 15844kb | C++14 | 751b | 2024-05-15 20:36:57 | 2024-05-15 20:36:58 |
Judging History
answer
#include <iostream>
using namespace std;
#include <algorithm>
#include <vector>
typedef long long ll;
const int N = 1e7 + 10;
int mod = 998244353;
ll a[N];
ll fast_pow(ll a, int n)
{
ll res = 1;
while (n)
{
if (n & 1)
res = (res * a) % mod;
n >>= 1;
a = (a * a) % mod;
}
return res % mod;
}
int main()
{
ll n;
cin >> n;
a[0] = 1;
for (int i = 1; i <= n; i++)
a[i] = ((a[i - 1] % mod) * (i % mod)) % mod;
int s = 0LL;
for (int i = 1; i <= n; i++)
{
if (n - i >= i - 1)
s = (s + (((a[n - i]) % mod * fast_pow(a[n - i - i + 1], mod - 2)) % mod * a[n - i]) % mod) % mod;
}
cout << s % mod << "\n";
}
详细
Test #1:
score: 100
Accepted
time: 0ms
memory: 3604kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3584kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3660kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 3728kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3716kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3596kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 3648kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3644kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3656kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 3656kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 3656kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 3660kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 3608kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 192ms
memory: 15844kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: -100
Time Limit Exceeded
input:
7579013
output:
827172636