enumerate/bits.hpp

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• Last update: 2026-07-26 20:34:09+09:00
• Include: #include "enumerate/bits.hpp"

Depends on

• other/bit.hpp

Required by

• enumerate/partition.hpp
• graph/count/count_cycle.hpp
• graph/minimum_hamiltonian_cycle.hpp
• graph/steiner_tree.hpp
• knapsack/subset_sum.hpp
• linalg/hafnian.hpp
• setfunc/online/online_or_convolution.hpp
• setfunc/online/online_subset_mobius.hpp
• setfunc/online/online_subset_zeta.hpp
• setfunc/submask_range_query.hpp

Verified with

• test/1_mytest/enum_partitions.test.cpp
• test/1_mytest/subset_sum.test.cpp
• test/2_library_checker/linear_algebra/hafnian_of_matrix.test.cpp
• test/3_yukicoder/114.test.cpp
• test/3_yukicoder/1263.test.cpp
• test/3_yukicoder/1881.test.cpp
• test/3_yukicoder/2507.test.cpp
• test/3_yukicoder/4_2.test.cpp
• test/4_aoj/DPL_2_A.test.cpp

Code

#include "other/bit.hpp"
template <typename BS, typename F>
void enumerate_bits_bitset(BS& b, int L, int R, F&& f) {
  if (L >= len(b)) return;
  int p = (b[L] ? L : b._Find_next(L));
  while (p < R) {
    f(p);
    p = b._Find_next(p);
  }
}

template <typename UINT, typename F>
inline void enumerate_all_bit(UINT s, F&& f) {
  static_assert(is_unsigned<UINT>::value);
  while (s) {
    f(lowbit(s));
    s &= s - 1;
  }
}

template <typename UINT, bool inc_empty, typename F>
inline void enumerate_all_subset(UINT s, F&& f) {
  static_assert(is_unsigned<UINT>::value);
  for (UINT t = s; t; t = (t - 1) & s) f(t);
  if constexpr (inc_empty) f(0);
}

#line 2 "other/bit.hpp"

int popcnt(int x) { return __builtin_popcount(x); }
int popcnt(u32 x) { return __builtin_popcount(x); }
int popcnt(ll x) { return __builtin_popcountll(x); }
int popcnt(u64 x) { return __builtin_popcountll(x); }
int popcnt_sgn(int x) { return (__builtin_parity(unsigned(x)) & 1 ? -1 : 1); }
int popcnt_sgn(u32 x) { return (__builtin_parity(x) & 1 ? -1 : 1); }
int popcnt_sgn(ll x) { return (__builtin_parityll(x) & 1 ? -1 : 1); }
int popcnt_sgn(u64 x) { return (__builtin_parityll(x) & 1 ? -1 : 1); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 1, 2)
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(u32 x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int topbit(u64 x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 0, 2)
int lowbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(u32 x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
int lowbit(u64 x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }

template <typename T>
T kth_bit(int k) {
  return T(1) << k;
}
template <typename T>
bool has_kth_bit(T x, int k) {
  return x >> k & 1;
}

template <typename UINT>
struct all_bit {
  UINT s;
  struct iter {
    UINT s;
    int operator*() const { return lowbit(s); }
    void operator++() { s &= s - 1; }
    bool operator!=(nullptr_t) const { return s; }
  };
  iter begin() const { return {s}; }
  nullptr_t end() const { return nullptr; }
};

template <typename UINT>
struct all_subset {
  UINT s;
  struct iter {
    UINT s, t;
    bool done = false;
    UINT operator*() const { return t; }
    void operator++() {
      done = (t == 0);
      t = (t - 1) & s;
    }
    bool operator!=(nullptr_t) const { return !done; }
  };
  iter begin() const { return {s, s}; }
  nullptr_t end() const { return nullptr; }
};

constexpr u64 full_mask(int n) { return n == 64 ? -1ULL : (1ULL << n) - 1; }
#line 2 "enumerate/bits.hpp"
template <typename BS, typename F>
void enumerate_bits_bitset(BS& b, int L, int R, F&& f) {
  if (L >= len(b)) return;
  int p = (b[L] ? L : b._Find_next(L));
  while (p < R) {
    f(p);
    p = b._Find_next(p);
  }
}

template <typename UINT, typename F>
inline void enumerate_all_bit(UINT s, F&& f) {
  static_assert(is_unsigned<UINT>::value);
  while (s) {
    f(lowbit(s));
    s &= s - 1;
  }
}

template <typename UINT, bool inc_empty, typename F>
inline void enumerate_all_subset(UINT s, F&& f) {
  static_assert(is_unsigned<UINT>::value);
  for (UINT t = s; t; t = (t - 1) & s) f(t);
  if constexpr (inc_empty) f(0);
}

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