QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#399352 | #6736. Alice and Bob | Kidding_Ma | AC ✓ | 118ms | 159960kb | C++14 | 1.1kb | 2024-04-26 11:01:59 | 2024-04-26 11:02:00 |
Judging History
answer
#include "bits/stdc++.h"
using namespace std;
using i64 = long long;
constexpr int P = 998244353;
i64 *fac, *ifac;
i64 power(i64 a, i64 b, int p = P) {
i64 res = 1;
for (; b; b >>= 1, a = a * a % p) {
if (b & 1) {
res = res * a % p;
}
}
return res;
}
i64 inv(i64 x) {
return power(x, P - 2, P);
}
void init(int N) {
fac = new i64 [N + 1];
ifac = new i64 [N + 1];
fac[0] = 1;
for (int i = 1; i <= N; i++) {
fac[i] = fac[i - 1] * i % P;
}
ifac[N] = inv(fac[N]);
for (int i = N - 1; i >= 0; i--) {
ifac[i] = ifac[i + 1] * (i + 1) % P;
}
}
i64 C(int n, int m) {
if (m < 0 || m > n || n < 0) {
return 0;
}
return fac[n] * ifac[m] % P * ifac[n - m] % P;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
init(1E7);
int n;
cin >> n;
i64 ans = 0;
for (int i = 1; i <= (n + 1) / 2; i++) {
ans = (ans + C(n - i, i - 1) * fac[n - i] % P * fac[i - 1]) % P;
}
cout << ans << '\n';
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 84ms
memory: 159908kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 85ms
memory: 159832kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 77ms
memory: 159836kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 86ms
memory: 159828kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 81ms
memory: 159872kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 84ms
memory: 159956kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 84ms
memory: 159892kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 80ms
memory: 159836kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 92ms
memory: 159956kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 85ms
memory: 159888kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 82ms
memory: 159960kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 92ms
memory: 159880kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 91ms
memory: 159836kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 91ms
memory: 159872kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 107ms
memory: 159896kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 108ms
memory: 159956kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 99ms
memory: 159900kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 101ms
memory: 159896kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 108ms
memory: 159956kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 75ms
memory: 159896kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 110ms
memory: 159880kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 110ms
memory: 159872kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 118ms
memory: 159904kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"