Count divisors
(Mylib/Number/Divisor/count_divisors.cpp)

• View this file on GitHub
• Last update: 2021-04-23 23:44:44+09:00

Operations

Requirements

Notes

Problems

References

Code

#pragma once
#include <cstdint>

namespace haar_lib {
  constexpr int count_divisors(int64_t n) {
    int count = 0;
    for (int64_t i = 1LL; i * i <= n; ++i) {
      if (n % i == 0) {
        count += 2;
        if (i * i == n) count -= 1;
      }
    }
    return count;
  }
}  // namespace haar_lib

#line 2 "Mylib/Number/Divisor/count_divisors.cpp"
#include <cstdint>

namespace haar_lib {
  constexpr int count_divisors(int64_t n) {
    int count = 0;
    for (int64_t i = 1LL; i * i <= n; ++i) {
      if (n % i == 0) {
        count += 2;
        if (i * i == n) count -= 1;
      }
    }
    return count;
  }
}  // namespace haar_lib

Back to top page