atcoder/fenwicktree.hpp

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• Last update: 2024-09-27 00:07:49+09:00
• Include: #include "atcoder/fenwicktree.hpp"
• Link: https://en.wikipedia.org/wiki/Fenwick_tree

Depends on

• atcoder/internal_type_traits.hpp

Required by

• 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_FENWICKTREE_HPP
#define ATCODER_FENWICKTREE_HPP 1

#include <cassert>
#include <vector>

#include "atcoder/internal_type_traits"

namespace atcoder {

// Reference: https://en.wikipedia.org/wiki/Fenwick_tree
template <class T> struct fenwick_tree {
    using U = internal::to_unsigned_t<T>;

  public:
    fenwick_tree() : _n(0) {}
    explicit fenwick_tree(int n) : _n(n), data(n) {}

    void add(int p, T x) {
        assert(0 <= p && p < _n);
        p++;
        while (p <= _n) {
            data[p - 1] += U(x);
            p += p & -p;
        }
    }

    T sum(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        return sum(r) - sum(l);
    }

  private:
    int _n;
    std::vector<U> data;

    U sum(int r) {
        U s = 0;
        while (r > 0) {
            s += data[r - 1];
            r -= r & -r;
        }
        return s;
    }
};

}  // namespace atcoder

#endif  // ATCODER_FENWICKTREE_HPP

#line 1 "atcoder/fenwicktree.hpp"



#include <cassert>
#include <vector>

#line 1 "atcoder/internal_type_traits.hpp"



#line 5 "atcoder/internal_type_traits.hpp"
#include <numeric>
#include <type_traits>

namespace atcoder {

namespace internal {

#ifndef _MSC_VER
template <class T>
using is_signed_int128 =
    typename std::conditional<std::is_same<T, __int128_t>::value ||
                                  std::is_same<T, __int128>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using is_unsigned_int128 =
    typename std::conditional<std::is_same<T, __uint128_t>::value ||
                                  std::is_same<T, unsigned __int128>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using make_unsigned_int128 =
    typename std::conditional<std::is_same<T, __int128_t>::value,
                              __uint128_t,
                              unsigned __int128>;

template <class T>
using is_integral = typename std::conditional<std::is_integral<T>::value ||
                                                  is_signed_int128<T>::value ||
                                                  is_unsigned_int128<T>::value,
                                              std::true_type,
                                              std::false_type>::type;

template <class T>
using is_signed_int = typename std::conditional<(is_integral<T>::value &&
                                                 std::is_signed<T>::value) ||
                                                    is_signed_int128<T>::value,
                                                std::true_type,
                                                std::false_type>::type;

template <class T>
using is_unsigned_int =
    typename std::conditional<(is_integral<T>::value &&
                               std::is_unsigned<T>::value) ||
                                  is_unsigned_int128<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using to_unsigned = typename std::conditional<
    is_signed_int128<T>::value,
    make_unsigned_int128<T>,
    typename std::conditional<std::is_signed<T>::value,
                              std::make_unsigned<T>,
                              std::common_type<T>>::type>::type;

#else

template <class T> using is_integral = typename std::is_integral<T>;

template <class T>
using is_signed_int =
    typename std::conditional<is_integral<T>::value && std::is_signed<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using is_unsigned_int =
    typename std::conditional<is_integral<T>::value &&
                                  std::is_unsigned<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using to_unsigned = typename std::conditional<is_signed_int<T>::value,
                                              std::make_unsigned<T>,
                                              std::common_type<T>>::type;

#endif

template <class T>
using is_signed_int_t = std::enable_if_t<is_signed_int<T>::value>;

template <class T>
using is_unsigned_int_t = std::enable_if_t<is_unsigned_int<T>::value>;

template <class T> using to_unsigned_t = typename to_unsigned<T>::type;

}  // namespace internal

}  // namespace atcoder


#line 8 "atcoder/fenwicktree.hpp"

namespace atcoder {

// Reference: https://en.wikipedia.org/wiki/Fenwick_tree
template <class T> struct fenwick_tree {
    using U = internal::to_unsigned_t<T>;

  public:
    fenwick_tree() : _n(0) {}
    explicit fenwick_tree(int n) : _n(n), data(n) {}

    void add(int p, T x) {
        assert(0 <= p && p < _n);
        p++;
        while (p <= _n) {
            data[p - 1] += U(x);
            p += p & -p;
        }
    }

    T sum(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        return sum(r) - sum(l);
    }

  private:
    int _n;
    std::vector<U> data;

    U sum(int r) {
        U s = 0;
        while (r > 0) {
            s += data[r - 1];
            r -= r & -r;
        }
        return s;
    }
};

}  // namespace atcoder

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