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QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #640899 | #5. 在线 O(1) 逆元 | masterhuang | 100 ✓ | 5506ms | 7984kb | C++20 | 349b | 2024-10-14 16:48:52 | 2024-11-05 22:05:48 |
Judging History
answer
#include "inv.h"
#include<bits/stdc++.h>
using namespace std;
const int N=1<<20|5,mod=998244353;
int n=N-5,I[N];
void init(int p)
{
I[1]=1;
for(int i=2;i<=n;i++) I[i]=mod-1ll*(mod/i)*I[mod%i]%mod;
}
int inv(int x)
{
if(x<=n) return I[x];int q=mod/x,r=mod%x;
if(r<x/2) return mod-1ll*q*inv(r)%mod;
return 1ll*(q+1)*inv(x-r)%mod;
}
Details
Pretests
Final Tests
Test #1:
score: 10
Accepted
time: 11ms
memory: 7824kb
Test #2:
score: 20
Accepted
time: 554ms
memory: 7960kb
Test #3:
score: 30
Accepted
time: 2748ms
memory: 7764kb
Test #4:
score: 20
Accepted
time: 4390ms
memory: 7844kb
Test #5:
score: 20
Accepted
time: 5506ms
memory: 7984kb