QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#398649 | #6736. Alice and Bob | qionghua | TL | 931ms | 134340kb | C++14 | 1.7kb | 2024-04-25 16:11:11 | 2024-04-25 16:11:13 |
Judging History
answer
#include <bits/stdc++.h>
#include <chrono>
using namespace std;
#define endl '\n'
//#define inf 1e18
typedef long long ll;
typedef unsigned long long ull;
typedef __int128 lll;
typedef pair<ll, ll> P;
#define x first
#define y second
#define int long long
// const int p = 1e9 + 7;
const int pp = 998244353;
int dx[8] = {-1, 0, 1, 0, -1, -1, 1, 1}, dy[8] = {0, 1, 0, -1, -1, 1, -1, 1};
int ddx[8] = {1, 1, 2, 2, -1, -1, -2, -2}, ddy[8] = {2, -2, 1, -1, 2, -2, 1, -1};
ll ksm(ll a, ll b, ll p) {
ll ans = 1;
while(b) {
if(b & 1) ans = (ans * a) % p;
b >>= 1;
a = (a * a) % p;
}
return ans % p;
}
std::mt19937 rng; // 随机数生成器
int rand(int l, int r) {
std::uniform_int_distribution<int> distribution(l, r);
return distribution(rng);
}
const int N = 1e7 + 1;
int f[N], g[N];
void init(int n) {
f[0] = g[0] = f[1] = g[1] = 1;
for(int i = 2; i <= n; ++i) {
f[i] = f[i - 1] * i % pp;
g[i] = g[i - 1] * ksm(i, pp - 2, pp) % pp;
}
}
int C(int a, int b) {
if(a < b) return 0;
return f[a] * g[b] % pp * g[a - b] % pp;
}
void solve() {
int n;
cin >> n;
init(n);
int ans = 0;
for(int p1 = 1; p1 <= n / 2 + 1; ++ p1) {
int now = C(n - p1, p1 - 1) * f[p1 - 1] % pp * f[n - p1] % pp;
// cout << "p1 : " << p1 << ", now : " << now << endl;
ans = (ans + now) % pp;
}
cout << ans << endl;
}
/*
*/
signed main () {
// init(minp, primes, m); // primes
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
int _ = 1;
// cin >> _;
while(_ -- ) {
solve();
}
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 5696kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 5700kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 0ms
memory: 5712kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 5636kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 0ms
memory: 5760kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 5636kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 5712kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 1ms
memory: 5640kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 5756kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 5756kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 1ms
memory: 5704kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 1ms
memory: 5644kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 0ms
memory: 5652kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 162ms
memory: 27140kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 878ms
memory: 125100kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 931ms
memory: 134340kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 716ms
memory: 101516kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 412ms
memory: 60724kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 804ms
memory: 117264kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 337ms
memory: 52736kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: -100
Time Limit Exceeded
input:
9999998