atcoder/internal_bit.hpp

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• Last update: 2024-09-27 00:07:49+09:00
• Include: #include "atcoder/internal_bit.hpp"

Required by

• atcoder/convolution.hpp
• atcoder/lazysegtree.hpp
• atcoder/segtree.hpp
• Formal Power Series (formal_power_series.hpp)
• math_fps.hpp
• Area of Union of Rectangles (rectangle_union.hpp)
• template.hpp

Verified with

• test/aoj_dsl_a_range_minimum_query.cpp
• test/aoj_dsl_b_range_sum_query.cpp
• test/aoj_dsl_d_range_update_query.cpp
• test/aoj_dsl_e_range_add_query.cpp
• test/aoj_dsl_e_range_add_query_2.cpp
• test/lc_area_of_union_of_rectangles.cpp
• test/lc_associative_array_dynamic_hash_map.cpp
• test/lc_associative_array_dynamic_hash_map_reserve.cpp
• test/lc_associative_array_hash_map.cpp
• test/lc_binomial_coefficient.cpp
• test/lc_cartesian_tree.cpp
• test/lc_discrete_logarithm.cpp
• test/lc_enumerate_palindromes.cpp
• test/lc_exp_of_formal_power_series.cpp
• test/lc_factorial.cpp
• test/lc_factorize.cpp
• test/lc_gcd_convolution.cpp
• test/lc_inv_of_formal_power_series.cpp
• test/lc_kth_term_of_linearly_recurrent_sequence.cpp
• test/lc_lcm_convolution.cpp
• test/lc_line_add_get_min.cpp
• test/lc_log_of_formal_power_series.cpp
• test/lc_multipoint_evaluation.cpp
• test/lc_point_add_rectangle_sum.cpp
• test/lc_point_set_range_composite.cpp
• test/lc_point_set_range_composite_large.cpp
• test/lc_pow_of_formal_power_series.cpp
• test/lc_primality_test.cpp
• test/lc_primality_test_montgomery.cpp
• test/lc_primitive_root.cpp
• test/lc_product_of_polynomial_sequence.cpp
• test/lc_range_affine_point_get.cpp
• test/lc_range_kth_smallest.cpp
• test/lc_rectangle_sum.cpp
• test/lc_segment_add_get_min.cpp
• test/lc_set_xor_min.cpp
• test/lc_static_range_frequency.cpp
• test/lc_static_range_mode_query.cpp
• test/lc_staticrmq.cpp
• test/lc_unionfind_with_potential.cpp
• test/lc_wildcard_pattern_matching.cpp
• test/lc_wildcard_pattern_matching_deterministic.cpp

Code

#ifndef ATCODER_INTERNAL_BITOP_HPP
#define ATCODER_INTERNAL_BITOP_HPP 1

#ifdef _MSC_VER
#include <intrin.h>
#endif

#if __cplusplus >= 202002L
#include <bit>
#endif

namespace atcoder {

namespace internal {

#if __cplusplus >= 202002L

using std::bit_ceil;

#else

// @return same with std::bit::bit_ceil
unsigned int bit_ceil(unsigned int n) {
    unsigned int x = 1;
    while (x < (unsigned int)(n)) x *= 2;
    return x;
}

#endif

// @param n `1 <= n`
// @return same with std::bit::countr_zero
int countr_zero(unsigned int n) {
#ifdef _MSC_VER
    unsigned long index;
    _BitScanForward(&index, n);
    return index;
#else
    return __builtin_ctz(n);
#endif
}

// @param n `1 <= n`
// @return same with std::bit::countr_zero
constexpr int countr_zero_constexpr(unsigned int n) {
    int x = 0;
    while (!(n & (1 << x))) x++;
    return x;
}

}  // namespace internal

}  // namespace atcoder

#endif  // ATCODER_INTERNAL_BITOP_HPP

#line 1 "atcoder/internal_bit.hpp"



#ifdef _MSC_VER
#include <intrin.h>
#endif

#if __cplusplus >= 202002L
#include <bit>
#endif

namespace atcoder {

namespace internal {

#if __cplusplus >= 202002L

using std::bit_ceil;

#else

// @return same with std::bit::bit_ceil
unsigned int bit_ceil(unsigned int n) {
    unsigned int x = 1;
    while (x < (unsigned int)(n)) x *= 2;
    return x;
}

#endif

// @param n `1 <= n`
// @return same with std::bit::countr_zero
int countr_zero(unsigned int n) {
#ifdef _MSC_VER
    unsigned long index;
    _BitScanForward(&index, n);
    return index;
#else
    return __builtin_ctz(n);
#endif
}

// @param n `1 <= n`
// @return same with std::bit::countr_zero
constexpr int countr_zero_constexpr(unsigned int n) {
    int x = 0;
    while (!(n & (1 << x))) x++;
    return x;
}

}  // namespace internal

}  // namespace atcoder

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