Tifa's CP Library

src/math/sum_ik_flist/lib.hpp

• View this file on GitHub
• Last update: 2026-05-21 12:41:07+08:00
• Include: #include "src/math/sum_ik_flist/lib.hpp"

Depends on

• src/util/util/lib.hpp

Required by

• src/nt/mfsum/min25/lib.hpp

Verified with

• test/cpv/library-checker-number_theory/sum_of_totient_function.min25.mintd-bd.cpp
• test/cpv/library-checker-number_theory/sum_of_totient_function.min25.mintd-md.cpp
• test/cpv/library-checker-number_theory/sum_of_totient_function.min25.mintd-md64.cpp
• test/cpv/library-checker-number_theory/sum_of_totient_function.min25.mints-bs.cpp
• test/cpv/library-checker-number_theory/sum_of_totient_function.min25.mints-ms.cpp
• test/cpv/library-checker-number_theory/sum_of_totient_function.min25.mints-ms64.cpp
• test/cpv_local/math/sum_ik_flist.cpp

Code

#pragma once

#include "../../util/util/lib.hpp"

namespace tifa_libs {

template <class T>
CEXP T sum_i0(T n) NE { return n; }
template <class T>
CEXP T sum_i1(T n) NE { return n * (n + 1) / 2; }
template <class T>
CEXP T sum_i2(T n) NE { return sum_i1(n) * (n * 2 + 1) / 3; }
template <class T>
CEXP T sum_i3(T n) NE {
  const auto _ = sum_i1(n);
  return _ * _;
}
template <class T>
CEXP T sum_i4(T n) NE { return sum_i2(n) * (sum_i1(n) * 6 - 1) / 5; }
template <class T>
CEXP T sum_i5(T n) NE { return sum_i3(n) * (sum_i1(n) * 4 - 1) / 3; }
template <class T>
CEXP T sum_i6(T n) NE {
  const auto _ = sum_i1(n);
  return sum_i2(n) * (_ * (_ * 2 - 1) * 6 + 1) / 7;
}
template <class T>
CEXP T sum_i7(T n) NE {
  const auto _ = sum_i3(n);
  return _ * _ * 2 - sum_i5(n);
}

template <class T>
// NOLINTNEXTLINE(modernize-avoid-c-arrays)
CEXP T (*sum_ik[])(T) NE = {sum_i0<T>, sum_i1<T>, sum_i2<T>, sum_i3<T>, sum_i4<T>, sum_i5<T>, sum_i6<T>, sum_i7<T>};

}  // namespace tifa_libs

#line 2 "src/math/sum_ik_flist/lib.hpp"

#line 2 "src/util/util/lib.hpp"
// https://github.com/Tiphereth-A/CP-lib
#include <bits/extc++.h>
// clang-format off
namespace tifa_libs {

#define CEXP constexpr
#define CEXPE constexpr explicit
#define CR const&
#define CP const*
#define PC *const
#define CPC const*const
#define TPN typename
#define NE noexcept
#define CNE const noexcept
#define ND [[nodiscard]]
#define cT_(...) std::conditional_t<sizeof(__VA_ARGS__) <= sizeof(size_t) * 2, __VA_ARGS__, __VA_ARGS__ CR>
// NOLINTNEXTLINE(misc-const-correctness)
#define flt_(T, i, l, r, ...) for (T i = (l), i##e = (r)__VA_OPT__(, ) __VA_ARGS__; i < i##e; ++i)
#define retif_(cond, if_true, ...) if cond return if_true __VA_OPT__(; else return __VA_ARGS__)
#ifdef ONLINE_JUDGE
#undef assert
#define assert(x) 42
#endif

using namespace std::ranges;
using namespace std::literals;

template <class T>
CEXP T abs(T x) NE { retif_((x < 0), -x, x); }

}  // namespace tifa_libs
// clang-format on
#line 4 "src/math/sum_ik_flist/lib.hpp"

namespace tifa_libs {

template <class T>
CEXP T sum_i0(T n) NE { return n; }
template <class T>
CEXP T sum_i1(T n) NE { return n * (n + 1) / 2; }
template <class T>
CEXP T sum_i2(T n) NE { return sum_i1(n) * (n * 2 + 1) / 3; }
template <class T>
CEXP T sum_i3(T n) NE {
  const auto _ = sum_i1(n);
  return _ * _;
}
template <class T>
CEXP T sum_i4(T n) NE { return sum_i2(n) * (sum_i1(n) * 6 - 1) / 5; }
template <class T>
CEXP T sum_i5(T n) NE { return sum_i3(n) * (sum_i1(n) * 4 - 1) / 3; }
template <class T>
CEXP T sum_i6(T n) NE {
  const auto _ = sum_i1(n);
  return sum_i2(n) * (_ * (_ * 2 - 1) * 6 + 1) / 7;
}
template <class T>
CEXP T sum_i7(T n) NE {
  const auto _ = sum_i3(n);
  return _ * _ * 2 - sum_i5(n);
}

template <class T>
// NOLINTNEXTLINE(modernize-avoid-c-arrays)
CEXP T (*sum_ik[])(T) NE = {sum_i0<T>, sum_i1<T>, sum_i2<T>, sum_i3<T>, sum_i4<T>, sum_i5<T>, sum_i6<T>, sum_i7<T>};

}  // namespace tifa_libs

Back to top page

This site is open source. Improve this page.