monoids/linear_function_plus_count_action.hpp

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• Last update: 2021-08-30 04:35:37+09:00
• Include: #include "monoids/linear_function_plus_count_action.hpp"

Depends on

• monoids/linear_function.hpp

Verified with

• data_structure/lazy_propagation_red_black_tree.range_affine_range_sum.test.cpp
• data_structure/lazy_propagation_segment_tree.range_affine_range_sum.test.cpp

Code

#pragma once
#include <utility>
#include "../monoids/linear_function.hpp"

/**
 * @note lazy_propagation_segment_tree<plus_count_monoid<T>, linear_function_monoid<T>, linear_function_plus_count_action<T> >
 */
template <class T>
struct linear_function_plus_count_action {
    typename plus_count_monoid<T>::value_type operator () (typename linear_function_monoid<T>::value_type f, typename plus_count_monoid<T>::value_type x) const {
        return std::make_pair(f.first * x.first + f.second * x.second, x.second);
    }
};

#line 2 "monoids/linear_function_plus_count_action.hpp"
#include <utility>
#line 3 "monoids/linear_function.hpp"

template <class CommutativeRing>
struct linear_function_monoid {
    typedef std::pair<CommutativeRing, CommutativeRing> value_type;
    linear_function_monoid() = default;
    value_type unit() const {
        return std::make_pair(1, 0);
    }
    value_type mult(value_type g, value_type f) const {
        CommutativeRing fst = g.first * f.first;
        CommutativeRing snd = g.second + g.first * f.second;
        return std::make_pair(fst, snd);
    }
};
#line 4 "monoids/linear_function_plus_count_action.hpp"

/**
 * @note lazy_propagation_segment_tree<plus_count_monoid<T>, linear_function_monoid<T>, linear_function_plus_count_action<T> >
 */
template <class T>
struct linear_function_plus_count_action {
    typename plus_count_monoid<T>::value_type operator () (typename linear_function_monoid<T>::value_type f, typename plus_count_monoid<T>::value_type x) const {
        return std::make_pair(f.first * x.first + f.second * x.second, x.second);
    }
};

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