nt/divisors.hpp

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

Depends on

prelude.hpp

Code

#pragma once

#include "prelude.hpp"

vector<ll> divisors(ll n) {
  assert(n > 0);
  vector<ll> small, big;
  for (ll d = 1; d * d <= n; d++) if (n % d == 0)
    small.push_back(d), big.push_back(n / d);
  if (small.back() == big.back()) big.pop_back();
  small.insert(small.end(), big.rbegin(), big.rend());
  return small;
}

#line 2 "nt/divisors.hpp"

#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 4 "nt/divisors.hpp"

vector<ll> divisors(ll n) {
  assert(n > 0);
  vector<ll> small, big;
  for (ll d = 1; d * d <= n; d++) if (n % d == 0)
    small.push_back(d), big.push_back(n / d);
  if (small.back() == big.back()) big.pop_back();
  small.insert(small.end(), big.rbegin(), big.rend());
  return small;
}