QOJ.ac
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 |
---|---|---|---|---|---|---|---|---|---|
#386753 | #6736. Alice and Bob | Arnold_6# | AC ✓ | 168ms | 238100kb | C++14 | 1000b | 2024-04-11 19:51:17 | 2024-04-11 19:51:17 |
Judging History
answer
# include <bits/stdc++.h>
using namespace std;
const int N = 1e7 + 10, mod = 998244353;
typedef long long LL;
int n;
LL fact[N], infact[N], inv[N];
int qp(int a, int k)
{
int res = 1;
while(k)
{
if(k & 1) res = (LL)res * a % mod;
a = (LL) a * a % mod;
k >>= 1;
}
return res;
}
void init()
{
fact[0] = infact[0] = 1;
inv[1] = 1;
for(int i = 2; i < N; i ++) inv[i] = (LL)(mod - mod / i) * inv[mod % i] % mod;
for(int i = 1; i < N; i ++)
{
fact[i] = (LL)fact[i - 1] * i % mod;
infact[i] = (LL)infact[i - 1] * inv[i] % mod;
}
}
int A(int y, int x)
{
return (LL)fact[x] * infact[x - y] % mod;
}
int main()
{
init();
cin >> n;
LL res = 0;
for(int i = 1; i <= (n + 1) / 2; i ++)
{
LL ans = (LL)A(i - 1, n - i) * fact[n - i] % mod;
res = (res + ans) % mod;
}
cout << res << endl;
//system("pause");
return 0;
}
詳細信息
Test #1:
score: 100
Accepted
time: 168ms
memory: 237884kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 124ms
memory: 238064kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 135ms
memory: 238008kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 130ms
memory: 237884kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 115ms
memory: 237884kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 119ms
memory: 238100kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 144ms
memory: 238008kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 134ms
memory: 237944kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 150ms
memory: 238008kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 127ms
memory: 238012kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 136ms
memory: 238096kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 150ms
memory: 237928kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 117ms
memory: 238020kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 116ms
memory: 238000kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 162ms
memory: 237888kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 139ms
memory: 237884kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 141ms
memory: 238008kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 143ms
memory: 238008kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 168ms
memory: 238024kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 155ms
memory: 238012kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 146ms
memory: 237936kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 163ms
memory: 238012kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 162ms
memory: 237964kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"