sorted_vector.hpp

/*********************************************************************
 *
 * Linear Arrangement Library - A library that implements a collection
 * algorithms for linear arrangments of graphs.
 *
 * Copyright (C) 2019 - 2024
 *
 * This file is part of Linear Arrangement Library. The full code is available
 * at:
 *      https://github.com/LAL-project/linear-arrangement-library.git
 *
 * Linear Arrangement Library is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Linear Arrangement Library is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Linear Arrangement Library.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Contact:
 *
 *     Lluís Alemany Puig (lluis.alemany.puig@upc.edu)
 *         LQMC (Quantitative, Mathematical, and Computational Linguisitcs)
 *         CQL (Complexity and Quantitative Linguistics Lab)
 *         Jordi Girona St 1-3, Campus Nord UPC, 08034 Barcelona.   CATALONIA, SPAIN
 *         Webpage: https://cqllab.upc.edu/people/lalemany/
 *
 *     Ramon Ferrer i Cancho (rferrericancho@cs.upc.edu)
 *         LQMC (Quantitative, Mathematical, and Computational Linguisitcs)
 *         CQL (Complexity and Quantitative Linguistics Lab)
 *         Office 220, Omega building
 *         Jordi Girona St 1-3, Campus Nord UPC, 08034 Barcelona.   CATALONIA, SPAIN
 *         Webpage: https://cqllab.upc.edu/people/rferrericancho/
 *
 ********************************************************************/
 
#pragma once
 
// C++ includes
#if defined DEBUG
#include <cassert>
#endif
#include <algorithm>
#include <vector>
 
namespace lal {
namespace detail {
namespace sorting {
 
template <class T, bool unique, typename allocator_t = std::allocator<T> >
class sorted_vector : public std::vector<T, allocator_t> {
public:
    using iterator_t = typename std::vector<T, allocator_t>::iterator;
 
    sorted_vector() noexcept : std::vector<T, allocator_t>() { }
    sorted_vector(const std::size_t n) noexcept : std::vector<T, allocator_t>(n) { }
    sorted_vector(const std::size_t n, const T& x) noexcept : std::vector<T, allocator_t>(n, x) { }
 
    sorted_vector(const sorted_vector& v) noexcept = default;
    sorted_vector(sorted_vector&& v) noexcept = default;
 
    [[nodiscard]] sorted_vector& operator= (const sorted_vector& v) noexcept = default;
    [[nodiscard]] sorted_vector& operator= (sorted_vector&& v) noexcept = default;
 
    ~sorted_vector() noexcept = default;
 
    iterator_t insert_sorted(const T& x) noexcept {
        if constexpr (not unique) {
            const auto it = std::upper_bound(this->begin(), this->end(), x);
            return this->insert(it, x);
        }
        else {
            if (this->size() == 0) {
                this->push_back(x);
                return this->begin();
            }
 
            const auto it = upper_bound(this->begin(), this->end(), x);
            const auto pre_it = it == this->begin() ? it : it - 1;
            if (*pre_it != x) {
                return this->insert(it, x);
            }
            return it;
        }
    }
    iterator_t insert_sorted(T&& x) noexcept {
        if constexpr (not unique) {
            const auto it = std::upper_bound(this->begin(), this->end(), x);
            return this->insert(it, std::forward<T>(x));
        }
        else {
            if (this->size() == 0) {
                this->push_back(std::forward<T>(x));
                return this->begin();
            }
 
            const auto it = std::upper_bound(this->begin(), this->end(), x);
            const auto pre_it = it == this->begin() ? it : it - 1;
            if (*pre_it != x) {
                return this->insert(it, std::forward<T>(x));
            }
            return it;
        }
    }
 
    iterator_t remove_sorted(const T& x) noexcept {
#if defined DEBUG
        assert(contains(x));
#endif
        const auto i1 = std::lower_bound(this->begin(), this->end(), x);
        return this->erase(i1);
    }
 
    [[nodiscard]] bool contains(const T& x) const noexcept {
        return std::binary_search(this->begin(), this->end(), x);
    }
 
    [[nodiscard]] iterator_t find_sorted(const T& x) noexcept {
        const auto i = std::lower_bound(this->begin(), this->end(), x);
        if (i == this->end()) { return this->end(); }
 
        if (*i == x) { return i; }
        return this->end();
    }
};
 
} // -- namespace sorting
} // -- namespace detail
} // -- namespace lal