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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#167014 | #5. 在线 O(1) 逆元 | OneWan | 100 ✓ | 1593ms | 24360kb | C++20 | 1.0kb | 2023-09-06 22:51:24 | 2024-11-05 21:52:17 |
Judging History
answer
#include "inv.h"
#include <bits/stdc++.h>
using namespace std;
const int B = 1 << 10, T = 1 << 20;
struct Inverse {
int mod;
int f[T + 1], p[T + 1], buf[T * 3 + 3], *I = buf + T;
Inverse(int mod) : mod(mod) {
for (int i = 1 ; i <= B ; i++) {
int s = 0, d = i << 10;
for (int j = 1 ; j <= T ; j++) {
if ((s += d) >= mod) s -= mod;
if (s <= T) {
if (f[j] == 0) {
f[j] = i;
p[j] = s;
}
} else if (s >= mod - T) {
if (f[j] == 0) {
f[j] = i;
p[j] = s - mod;
}
} else {
int t = (mod - T - s - 1) / d;
s += t * d;
j += t;
}
}
}
I[1] = f[0] = 1;
for (int i = 2 ; i <= T << 1 ; i++) {
I[i] = 1LL * (mod - mod / i) * I[mod % i] % mod;
}
for (int i = -1 ; i >= -T ; i--) {
I[i] = mod - I[-i];
}
}
int operator()(int x) {
return 1LL * I[p[x >> 10] + (x & 1023) * f[x >> 10]] * f[x >> 10] % mod;
}
}; // Inverse
void init(int p) {
}
Inverse invs(998244353);
int inv(int x) {
return invs(x);
}
Details
Pretests
Final Tests
Test #1:
score: 10
Accepted
time: 21ms
memory: 24236kb
Test #2:
score: 20
Accepted
time: 180ms
memory: 24180kb
Test #3:
score: 30
Accepted
time: 806ms
memory: 24360kb
Test #4:
score: 20
Accepted
time: 1281ms
memory: 24308kb
Test #5:
score: 20
Accepted
time: 1593ms
memory: 24360kb