QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#674727 | #6736. Alice and Bob | wysun | AC ✓ | 106ms | 81436kb | C++14 | 869b | 2024-10-25 17:19:36 | 2024-10-25 17:19:37 |
Judging History
answer
#include <iostream>
#include<vector>
using namespace std;
using i64 = long long;
const int P = 998244353;
int power(int a, int b)
{
int res = 1;
while(b)
{
if(b & 1) res = (i64)res * a % P;
a = (i64)a * a % P;
b >>= 1;
}
return res;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int n;
cin >> n;
vector<int> fac(n + 1), invfac(n + 1);
fac[0] = 1;
for (int i = 1; i <= n; i ++)
fac[i] = 1ll * fac[i - 1] * i % P;
invfac[n] = power(fac[n], P - 2);
for(int i = n - 1; i > 0; i --)
invfac[i] = 1ll * invfac[i + 1] * (i + 1) % P;
invfac[0] = 1;
int ans = 0;
for (int i = 1; n - i >= i - 1; i++)
ans = (ans + 1LL * fac[n - i] * invfac[n - i - (i - 1)] % P * fac[n - i]) % P;
cout << ans << endl;
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 3592kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3520kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3520kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 0ms
memory: 3744kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3804kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 0ms
memory: 3612kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 0ms
memory: 3592kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 3776kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 3808kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 3520kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 3516kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 3608kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 3752kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 17ms
memory: 13796kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 76ms
memory: 62348kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 80ms
memory: 66928kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 65ms
memory: 50968kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 38ms
memory: 30436kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 70ms
memory: 57692kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 30ms
memory: 25692kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 106ms
memory: 81088kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 104ms
memory: 81436kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 101ms
memory: 81212kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"