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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#214134 | #5. 在线 O(1) 逆元 | ucup-team1209 | 100 ✓ | 2749ms | 19288kb | C++20 | 842b | 2023-10-14 17:26:27 | 2023-10-14 17:26:28 |
Judging History
answer
#include<bits/stdc++.h>
#include"inv.h"
using std::cin;
using std::cout;
const int mod = 998244353;
const int mod2 = 974849;
const int w = sqrt(mod2);
const int limit = 3 * (w + 1) * 1024;
int djq[limit], arr[mod2];
using u64 = unsigned long long;
int inv(int x) {
const int p = (u64) x * arr[x >> 10] % mod;
return (u64) arr[x >> 10] * (p < limit ? djq[p] : mod - djq[mod - p]) % mod;
}
void init(int) {
for(int i = w;i >= 1;--i) {
std::function<int(int)> getinv = [&](int x) {
return x == 1 ? 1 : mod2 - u64(mod2 / x) * getinv(mod2 % x) % mod2;
};
int inv = getinv(i);
for(int j = 1;j <= w;++j) {
arr[(u64) j * inv % mod2] = i;
arr[mod2 - (u64) j * inv % mod2] = i;
}
}
arr[0] = 1;
djq[1] = 1;
for(int i = 2;i < limit;++i) {
djq[i] = mod - u64(mod / i) * djq[mod % i] % mod;
}
}
Details
Test #1:
score: 30
Accepted
time: 24ms
memory: 19288kb
Test #2:
score: 40
Accepted
time: 275ms
memory: 19268kb
Test #3:
score: 30
Accepted
time: 2749ms
memory: 19244kb