QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#362061 | #6736. Alice and Bob | proven# | AC ✓ | 122ms | 161828kb | C++20 | 1.7kb | 2024-03-23 14:01:13 | 2024-03-23 14:01:13 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define fs first
#define endl '\n'
#define sc second
#define pb push_back
#define int long long
#define bit(x) (1ll << (x))
#define sz(x) (int)(x).size()
#define al(x) (x).begin(),(x).end()
#define all(x) (x).begin() + 1,(x).end()
using LL = long long;
using VI = vector <int>;
using VS = vector <string>;
using PII = pair <int, int>;
using I64 = unsigned long long;
using VVI = vector < vector<int> >;
template<LL N> using AL = array<LL, N>;
template<int N> using AI = array<int, N>;
const int inf = bit(60), mod = 998244353, N = 1e7 + 6;
int fpow(int x, int t = mod - 2) {
int res = 1;
for (; t; t >>= 1, x = 1ll * x * x % mod)
if (t & 1) res = 1ll * res * x % mod;
return res;
}
int fac[N], ifac[N], deg[N], ans[N];
int C(int n, int m) {
if (n < m) return 0;
return 1ll * fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}
void init() //这里是处理阶乘和每个数字的逆元,fac[i]存的是i!,ifac[i]存的是i!的逆元,方便运算
{
fac[0] = ifac[0] = 1;
for (int i = 1; i < N; ++i) fac[i] = 1ll * fac[i - 1] * i % mod;
ifac[N - 1] = fpow(fac[N - 1]);
for (int i = N - 2; i; --i) ifac[i] = 1ll * ifac[i + 1] * (i + 1) % mod;
}
void solve() {
init();
int n; cin >> n;
int res = 0;
for(int i = 1;i * 2 - 1 <= n;i++) {
res = (res + C(n - i, i - 1) * fac[i - 1] % mod * fac[n - i] % mod) % mod;
}
cout << res << endl;
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cout << fixed << setprecision(10);
int T = 1;
// cin >> T;
while(T--) solve();
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 64ms
memory: 160816kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 36ms
memory: 160696kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 39ms
memory: 160460kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 56ms
memory: 160300kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 104ms
memory: 160784kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 75ms
memory: 160900kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 71ms
memory: 160660kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 80ms
memory: 160428kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 81ms
memory: 161360kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 95ms
memory: 161568kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 103ms
memory: 161488kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 88ms
memory: 160484kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 99ms
memory: 160184kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 91ms
memory: 160716kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 111ms
memory: 161672kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 85ms
memory: 161732kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 109ms
memory: 160968kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 101ms
memory: 160200kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 52ms
memory: 161828kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 83ms
memory: 161048kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 71ms
memory: 159984kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 122ms
memory: 160744kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 103ms
memory: 159904kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"