nt/moebius.hpp

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Last update: 2024-11-09 00:49:07+00:00
Include: #include "nt/moebius.hpp"

Depends on

prelude.hpp

Verified with

test/nt/convolve.test.cpp

Code

#pragma once
#include "prelude.hpp"

class moebius {
 public:
  moebius(int upto = 0) : mu(upto + 1, 1), prime(upto + 1, true) {
    prime[0] = prime[1] = false;
    for (int p = 2; p < size(); p++) if (prime[p]) {
      mu[p] *= -1;
      for (int m = p * 2; m < size(); m += p) mu[m] *= -1, prime[m] = false;
      if (1LL * p * p < size()) {
        for (int m = p * p; m < size(); m += p * p) mu[m] = 0;
      }
    }
  }
  int size() const { return mu.size(); }
  int operator[](int i) const { return mu[i]; }
  int operator()(int i) const { return mu[i]; }
  bool is_prime(int i) const { return prime[i]; }
  auto begin() const { return mu.cbegin(); }
  auto end() const { return mu.cend(); }
 private:
  vector<int> mu;
  vector<bool> prime;
};

#line 2 "prelude.hpp"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
using vc = vector<char>;
#define rep2(i, m, n) for (auto i = (m); i < (n); i++)
#define rep(i, n) rep2(i, 0, n)
#define repr2(i, m, n) for (auto i = (n); i-- > (m);)
#define repr(i, n) repr2(i, 0, n)
#define all(x) begin(x), end(x)
auto ndvec(int n, auto e) { return vector(n, e); }
auto ndvec(int n, auto ...e) { return vector(n, ndvec(e...)); }
auto comp_key(auto&& f) { return [&](auto&& a, auto&& b) { return f(a) < f(b); }; }
auto& max(const auto& a, const auto& b) { return a < b ? b : a; }
auto& min(const auto& a, const auto& b) { return b < a ? b : a; }
#if __cpp_lib_ranges
namespace R = std::ranges;
namespace V = std::views;
#endif
#line 3 "nt/moebius.hpp"

class moebius {
 public:
  moebius(int upto = 0) : mu(upto + 1, 1), prime(upto + 1, true) {
    prime[0] = prime[1] = false;
    for (int p = 2; p < size(); p++) if (prime[p]) {
      mu[p] *= -1;
      for (int m = p * 2; m < size(); m += p) mu[m] *= -1, prime[m] = false;
      if (1LL * p * p < size()) {
        for (int m = p * p; m < size(); m += p * p) mu[m] = 0;
      }
    }
  }
  int size() const { return mu.size(); }
  int operator[](int i) const { return mu[i]; }
  int operator()(int i) const { return mu[i]; }
  bool is_prime(int i) const { return prime[i]; }
  auto begin() const { return mu.cbegin(); }
  auto end() const { return mu.cend(); }
 private:
  vector<int> mu;
  vector<bool> prime;
};