QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#490939 | #8635. 圆 | KiharaTouma# | 20 | 12ms | 3976kb | C++23 | 551b | 2024-07-25 16:48:07 | 2024-07-25 16:48:09 |
Judging History
answer
//qoj8635
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 5010;
const ll P = 998244353;
int n;
ll f[N];
ll qp(ll x, ll y){
ll ans = 1;
while(y){
if(y & 1){
ans = ans * x % P;
}
x = x * x % P;
y >>= 1;
}
return ans;
}
int main(){
scanf("%d", &n);
for(int i = 1; i <= n; ++ i){
ll tmp = 0;
for(int j = 0; j <= i + 1; ++ j){
tmp += f[max(0, j-2)] + f[max(0, i-j-1)];
}
f[i] = tmp * qp(i+2, P-2) % P + 1;
}
printf("%lld\n", (f[n-3] + 1) % P);
return 0;
}
Details
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Pretests
Final Tests
Test #1:
score: 10
Accepted
time: 0ms
memory: 3948kb
input:
3
output:
1
result:
ok 1 number(s): "1"
Test #2:
score: 10
Accepted
time: 0ms
memory: 3792kb
input:
4
output:
2
result:
ok 1 number(s): "2"
Test #3:
score: 0
Wrong Answer
time: 0ms
memory: 3800kb
input:
6
output:
3
result:
wrong answer 1st numbers differ - expected: '299473309', found: '3'
Test #4:
score: 0
Wrong Answer
time: 0ms
memory: 3880kb
input:
10
output:
5
result:
wrong answer 1st numbers differ - expected: '487238321', found: '5'
Test #5:
score: 0
Wrong Answer
time: 0ms
memory: 3880kb
input:
100
output:
-90875623
result:
wrong answer 1st numbers differ - expected: '41620761', found: '-90875623'
Test #6:
score: 0
Wrong Answer
time: 0ms
memory: 3952kb
input:
200
output:
-923055229
result:
wrong answer 1st numbers differ - expected: '208771764', found: '-923055229'
Test #7:
score: 0
Wrong Answer
time: 1ms
memory: 3812kb
input:
500
output:
-515344982
result:
wrong answer 1st numbers differ - expected: '888621375', found: '-515344982'
Test #8:
score: 0
Wrong Answer
time: 11ms
memory: 3920kb
input:
4798
output:
952533544
result:
wrong answer 1st numbers differ - expected: '319137015', found: '952533544'
Test #9:
score: 0
Wrong Answer
time: 12ms
memory: 3976kb
input:
4999
output:
-655131513
result:
wrong answer 1st numbers differ - expected: '818467659', found: '-655131513'
Test #10:
score: 0
Wrong Answer
time: 12ms
memory: 3824kb
input:
5000
output:
-443461705
result:
wrong answer 1st numbers differ - expected: '142907477', found: '-443461705'