Enumerate divisors
(Mylib/Number/Divisor/enumerate_divisors.cpp)

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• Last update: 2021-04-23 23:44:44+09:00
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Operations

Requirements

Notes

Problems

References

Verified with

• test/aoj/ITP1_3_D/main.test.cpp

Code

#pragma once
#include <algorithm>
#include <vector>

namespace haar_lib {
  std::vector<int64_t> enumerate_divisors(int64_t n) {
    std::vector<int64_t> temp, ret;

    {
      int64_t i;
      for (i = 1LL; i * i < n; ++i) {
        if (n % i == 0) {
          temp.push_back(n / i);
          ret.push_back(i);
        }
      }
      if (i * i == n) ret.push_back(i);
    }

    std::reverse(temp.begin(), temp.end());
    ret.insert(ret.end(), temp.begin(), temp.end());

    return ret;
  }
}  // namespace haar_lib

#line 2 "Mylib/Number/Divisor/enumerate_divisors.cpp"
#include <algorithm>
#include <vector>

namespace haar_lib {
  std::vector<int64_t> enumerate_divisors(int64_t n) {
    std::vector<int64_t> temp, ret;

    {
      int64_t i;
      for (i = 1LL; i * i < n; ++i) {
        if (n % i == 0) {
          temp.push_back(n / i);
          ret.push_back(i);
        }
      }
      if (i * i == n) ret.push_back(i);
    }

    std::reverse(temp.begin(), temp.end());
    ret.insert(ret.end(), temp.begin(), temp.end());

    return ret;
  }
}  // namespace haar_lib

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