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QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #136491 | #5. 在线 O(1) 逆元 | zhouhuanyi | 100 ✓ | 5915ms | 42768kb | C++14 | 462b | 2023-08-08 20:59:24 | 2023-08-08 20:59:27 |
Judging History
answer
#include<iostream>
#include<cstdio>
#define mod 998244353
#define N 10000000
using namespace std;
int MD2(int x)
{
return x<0?x+mod:x;
}
int T,invs[N+1];
void init(int p)
{
invs[1]=1;
for (int i=2;i<=N;++i) invs[i]=MD2(-1ll*(mod/i)*invs[mod%i]%mod);
return;
}
int inv(int x)
{
int a,b;
if (x<=N) return invs[x];
else
{
a=mod/x,b=mod%x;
if ((b<<1)<=x) return 1ll*MD2(-a)*inv(b)%mod;
else return 1ll*(a+1)*inv(x-b)%mod;
}
}
Details
Test #1:
score: 30
Accepted
time: 69ms
memory: 42660kb
Test #2:
score: 40
Accepted
time: 705ms
memory: 42768kb
Test #3:
score: 30
Accepted
time: 5915ms
memory: 42660kb