QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#209181 | #6736. Alice and Bob | luhanning | AC ✓ | 113ms | 160776kb | C++14 | 1.1kb | 2023-10-10 11:22:31 | 2023-10-10 11:22:31 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e7 + 10;
const int mod = 998244353;
int n, m, k;
string s1, s2;
int h[N], idx, ne[N];
vector<int> pa;
double a, b;
int infact[N];
int fact[N];
int qmi(int a, int k, int p) {
int res = 1;
while (k) {
if (k & 1) res = res * a % p;
a = a * a % p;
k >>= 1;
}
return res;
}
void solve() {
cin >> n;
fact[0] = infact[0] = 1;
for (int i = 1; i < n; i++) {
fact[i] = fact[i - 1] * i % mod;
// infact[i] = infact[i - 1] * qmi(i, mod - 2, mod) % mod;
}
infact[n-1]=qmi(fact[n-1],mod-2,mod);
for(int i=n-2;i>=1;i--)
{
infact[i]=infact[i+1]*(i+1)%mod;
}
int ans = 0;
for (int i = 1; i <= n + 1; i++) {
if (n - i >= i - 1) {
int t1 = fact[n - i] % mod;
int t2 = fact[n - i] * infact[n + 1 - 2 * i] % mod;
ans = (ans + (t1 * t2) % mod) % mod;
}
}
//cout<<fact[3]<<endl;
cout << ans << endl;
}
signed main() {
int t = 1;
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
//cin >> t;
while (t--) {
solve();
}
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 7644kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 0
Accepted
time: 1ms
memory: 7696kb
input:
2
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 1ms
memory: 7696kb
input:
10
output:
997920
result:
ok 1 number(s): "997920"
Test #4:
score: 0
Accepted
time: 1ms
memory: 7776kb
input:
100
output:
188898954
result:
ok 1 number(s): "188898954"
Test #5:
score: 0
Accepted
time: 1ms
memory: 7788kb
input:
4
output:
10
result:
ok 1 number(s): "10"
Test #6:
score: 0
Accepted
time: 1ms
memory: 7768kb
input:
8
output:
12336
result:
ok 1 number(s): "12336"
Test #7:
score: 0
Accepted
time: 1ms
memory: 7704kb
input:
16
output:
373118483
result:
ok 1 number(s): "373118483"
Test #8:
score: 0
Accepted
time: 0ms
memory: 7756kb
input:
32
output:
314585464
result:
ok 1 number(s): "314585464"
Test #9:
score: 0
Accepted
time: 0ms
memory: 7772kb
input:
64
output:
627827331
result:
ok 1 number(s): "627827331"
Test #10:
score: 0
Accepted
time: 0ms
memory: 7700kb
input:
128
output:
828497685
result:
ok 1 number(s): "828497685"
Test #11:
score: 0
Accepted
time: 0ms
memory: 7708kb
input:
256
output:
65697890
result:
ok 1 number(s): "65697890"
Test #12:
score: 0
Accepted
time: 0ms
memory: 7832kb
input:
512
output:
854187619
result:
ok 1 number(s): "854187619"
Test #13:
score: 0
Accepted
time: 1ms
memory: 7712kb
input:
1024
output:
513823539
result:
ok 1 number(s): "513823539"
Test #14:
score: 0
Accepted
time: 7ms
memory: 29700kb
input:
1361956
output:
617368199
result:
ok 1 number(s): "617368199"
Test #15:
score: 0
Accepted
time: 92ms
memory: 126436kb
input:
7579013
output:
827172636
result:
ok 1 number(s): "827172636"
Test #16:
score: 0
Accepted
time: 91ms
memory: 135728kb
input:
8145517
output:
710624331
result:
ok 1 number(s): "710624331"
Test #17:
score: 0
Accepted
time: 23ms
memory: 104952kb
input:
6140463
output:
707600568
result:
ok 1 number(s): "707600568"
Test #18:
score: 0
Accepted
time: 45ms
memory: 64172kb
input:
3515281
output:
698302413
result:
ok 1 number(s): "698302413"
Test #19:
score: 0
Accepted
time: 76ms
memory: 119536kb
input:
6969586
output:
69470392
result:
ok 1 number(s): "69470392"
Test #20:
score: 0
Accepted
time: 37ms
memory: 54076kb
input:
2888636
output:
433579983
result:
ok 1 number(s): "433579983"
Test #21:
score: 0
Accepted
time: 69ms
memory: 160776kb
input:
9999998
output:
758172780
result:
ok 1 number(s): "758172780"
Test #22:
score: 0
Accepted
time: 106ms
memory: 160232kb
input:
9999999
output:
605195495
result:
ok 1 number(s): "605195495"
Test #23:
score: 0
Accepted
time: 113ms
memory: 160300kb
input:
10000000
output:
866813682
result:
ok 1 number(s): "866813682"