720 lines
18 KiB
C++
720 lines
18 KiB
C++
// SPDX-FileCopyrightText: 2002 Niels Provos <provos@citi.umich.edu>
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// SPDX-License-Identifier: BSD-2-Clause
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/* $NetBSD: tree.h,v 1.8 2004/03/28 19:38:30 provos Exp $ */
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/* $OpenBSD: tree.h,v 1.7 2002/10/17 21:51:54 art Exp $ */
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/* $FreeBSD$ */
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#pragma once
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/*
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* This file defines data structures for red-black trees.
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*
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* A red-black tree is a binary search tree with the node color as an
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* extra attribute. It fulfills a set of conditions:
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* - every search path from the root to a leaf consists of the
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* same number of black nodes,
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* - each red node (except for the root) has a black parent,
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* - each leaf node is black.
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*
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* Every operation on a red-black tree is bounded as O(lg n).
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* The maximum height of a red-black tree is 2lg (n+1).
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*/
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namespace Common::freebsd {
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enum class RBColor {
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RB_BLACK = 0,
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RB_RED = 1,
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};
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#pragma pack(push, 4)
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template <typename T>
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class RBEntry {
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public:
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constexpr RBEntry() = default;
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[[nodiscard]] constexpr T* Left() {
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return m_rbe_left;
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}
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[[nodiscard]] constexpr const T* Left() const {
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return m_rbe_left;
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}
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constexpr void SetLeft(T* e) {
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m_rbe_left = e;
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}
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[[nodiscard]] constexpr T* Right() {
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return m_rbe_right;
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}
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[[nodiscard]] constexpr const T* Right() const {
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return m_rbe_right;
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}
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constexpr void SetRight(T* e) {
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m_rbe_right = e;
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}
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[[nodiscard]] constexpr T* Parent() {
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return m_rbe_parent;
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}
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[[nodiscard]] constexpr const T* Parent() const {
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return m_rbe_parent;
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}
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constexpr void SetParent(T* e) {
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m_rbe_parent = e;
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}
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[[nodiscard]] constexpr bool IsBlack() const {
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return m_rbe_color == RBColor::RB_BLACK;
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}
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[[nodiscard]] constexpr bool IsRed() const {
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return m_rbe_color == RBColor::RB_RED;
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}
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[[nodiscard]] constexpr RBColor Color() const {
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return m_rbe_color;
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}
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constexpr void SetColor(RBColor c) {
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m_rbe_color = c;
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}
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private:
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T* m_rbe_left{};
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T* m_rbe_right{};
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T* m_rbe_parent{};
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RBColor m_rbe_color{RBColor::RB_BLACK};
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};
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#pragma pack(pop)
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template <typename T>
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struct CheckRBEntry {
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static constexpr bool value = false;
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};
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template <typename T>
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struct CheckRBEntry<RBEntry<T>> {
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static constexpr bool value = true;
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};
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template <typename T>
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concept IsRBEntry = CheckRBEntry<T>::value;
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template <typename T>
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concept HasRBEntry = requires(T& t, const T& ct) {
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{ t.GetRBEntry() } -> std::same_as<RBEntry<T>&>;
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{ ct.GetRBEntry() } -> std::same_as<const RBEntry<T>&>;
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};
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template <typename T>
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requires HasRBEntry<T>
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class RBHead {
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private:
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T* m_rbh_root = nullptr;
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public:
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[[nodiscard]] constexpr T* Root() {
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return m_rbh_root;
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}
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[[nodiscard]] constexpr const T* Root() const {
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return m_rbh_root;
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}
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constexpr void SetRoot(T* root) {
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m_rbh_root = root;
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}
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[[nodiscard]] constexpr bool IsEmpty() const {
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return this->Root() == nullptr;
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}
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};
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr RBEntry<T>& RB_ENTRY(T* t) {
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return t->GetRBEntry();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr const RBEntry<T>& RB_ENTRY(const T* t) {
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return t->GetRBEntry();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr T* RB_LEFT(T* t) {
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return RB_ENTRY(t).Left();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr const T* RB_LEFT(const T* t) {
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return RB_ENTRY(t).Left();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr T* RB_RIGHT(T* t) {
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return RB_ENTRY(t).Right();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr const T* RB_RIGHT(const T* t) {
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return RB_ENTRY(t).Right();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr T* RB_PARENT(T* t) {
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return RB_ENTRY(t).Parent();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr const T* RB_PARENT(const T* t) {
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return RB_ENTRY(t).Parent();
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_SET_LEFT(T* t, T* e) {
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RB_ENTRY(t).SetLeft(e);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_SET_RIGHT(T* t, T* e) {
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RB_ENTRY(t).SetRight(e);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_SET_PARENT(T* t, T* e) {
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RB_ENTRY(t).SetParent(e);
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr bool RB_IS_BLACK(const T* t) {
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return RB_ENTRY(t).IsBlack();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr bool RB_IS_RED(const T* t) {
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return RB_ENTRY(t).IsRed();
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}
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template <typename T>
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requires HasRBEntry<T>
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[[nodiscard]] constexpr RBColor RB_COLOR(const T* t) {
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return RB_ENTRY(t).Color();
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_SET_COLOR(T* t, RBColor c) {
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RB_ENTRY(t).SetColor(c);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_SET(T* elm, T* parent) {
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auto& rb_entry = RB_ENTRY(elm);
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rb_entry.SetParent(parent);
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rb_entry.SetLeft(nullptr);
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rb_entry.SetRight(nullptr);
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rb_entry.SetColor(RBColor::RB_RED);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_SET_BLACKRED(T* black, T* red) {
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RB_SET_COLOR(black, RBColor::RB_BLACK);
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RB_SET_COLOR(red, RBColor::RB_RED);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_ROTATE_LEFT(RBHead<T>& head, T* elm, T*& tmp) {
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tmp = RB_RIGHT(elm);
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if (RB_SET_RIGHT(elm, RB_LEFT(tmp)); RB_RIGHT(elm) != nullptr) {
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RB_SET_PARENT(RB_LEFT(tmp), elm);
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}
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if (RB_SET_PARENT(tmp, RB_PARENT(elm)); RB_PARENT(tmp) != nullptr) {
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if (elm == RB_LEFT(RB_PARENT(elm))) {
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RB_SET_LEFT(RB_PARENT(elm), tmp);
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} else {
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RB_SET_RIGHT(RB_PARENT(elm), tmp);
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}
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} else {
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head.SetRoot(tmp);
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}
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RB_SET_LEFT(tmp, elm);
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RB_SET_PARENT(elm, tmp);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_ROTATE_RIGHT(RBHead<T>& head, T* elm, T*& tmp) {
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tmp = RB_LEFT(elm);
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if (RB_SET_LEFT(elm, RB_RIGHT(tmp)); RB_LEFT(elm) != nullptr) {
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RB_SET_PARENT(RB_RIGHT(tmp), elm);
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}
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if (RB_SET_PARENT(tmp, RB_PARENT(elm)); RB_PARENT(tmp) != nullptr) {
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if (elm == RB_LEFT(RB_PARENT(elm))) {
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RB_SET_LEFT(RB_PARENT(elm), tmp);
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} else {
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RB_SET_RIGHT(RB_PARENT(elm), tmp);
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}
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} else {
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head.SetRoot(tmp);
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}
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RB_SET_RIGHT(tmp, elm);
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RB_SET_PARENT(elm, tmp);
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_REMOVE_COLOR(RBHead<T>& head, T* parent, T* elm) {
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T* tmp;
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while ((elm == nullptr || RB_IS_BLACK(elm)) && elm != head.Root()) {
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if (RB_LEFT(parent) == elm) {
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tmp = RB_RIGHT(parent);
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if (RB_IS_RED(tmp)) {
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RB_SET_BLACKRED(tmp, parent);
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RB_ROTATE_LEFT(head, parent, tmp);
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tmp = RB_RIGHT(parent);
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}
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if ((RB_LEFT(tmp) == nullptr || RB_IS_BLACK(RB_LEFT(tmp))) &&
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(RB_RIGHT(tmp) == nullptr || RB_IS_BLACK(RB_RIGHT(tmp)))) {
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RB_SET_COLOR(tmp, RBColor::RB_RED);
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elm = parent;
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parent = RB_PARENT(elm);
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} else {
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if (RB_RIGHT(tmp) == nullptr || RB_IS_BLACK(RB_RIGHT(tmp))) {
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T* oleft;
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if ((oleft = RB_LEFT(tmp)) != nullptr) {
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RB_SET_COLOR(oleft, RBColor::RB_BLACK);
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}
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RB_SET_COLOR(tmp, RBColor::RB_RED);
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RB_ROTATE_RIGHT(head, tmp, oleft);
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tmp = RB_RIGHT(parent);
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}
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RB_SET_COLOR(tmp, RB_COLOR(parent));
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RB_SET_COLOR(parent, RBColor::RB_BLACK);
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if (RB_RIGHT(tmp)) {
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RB_SET_COLOR(RB_RIGHT(tmp), RBColor::RB_BLACK);
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}
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RB_ROTATE_LEFT(head, parent, tmp);
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elm = head.Root();
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break;
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}
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} else {
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tmp = RB_LEFT(parent);
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if (RB_IS_RED(tmp)) {
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RB_SET_BLACKRED(tmp, parent);
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RB_ROTATE_RIGHT(head, parent, tmp);
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tmp = RB_LEFT(parent);
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}
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if ((RB_LEFT(tmp) == nullptr || RB_IS_BLACK(RB_LEFT(tmp))) &&
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(RB_RIGHT(tmp) == nullptr || RB_IS_BLACK(RB_RIGHT(tmp)))) {
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RB_SET_COLOR(tmp, RBColor::RB_RED);
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elm = parent;
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parent = RB_PARENT(elm);
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} else {
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if (RB_LEFT(tmp) == nullptr || RB_IS_BLACK(RB_LEFT(tmp))) {
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T* oright;
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if ((oright = RB_RIGHT(tmp)) != nullptr) {
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RB_SET_COLOR(oright, RBColor::RB_BLACK);
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}
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RB_SET_COLOR(tmp, RBColor::RB_RED);
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RB_ROTATE_LEFT(head, tmp, oright);
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tmp = RB_LEFT(parent);
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}
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RB_SET_COLOR(tmp, RB_COLOR(parent));
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RB_SET_COLOR(parent, RBColor::RB_BLACK);
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if (RB_LEFT(tmp)) {
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RB_SET_COLOR(RB_LEFT(tmp), RBColor::RB_BLACK);
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}
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RB_ROTATE_RIGHT(head, parent, tmp);
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elm = head.Root();
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break;
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}
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}
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}
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if (elm) {
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RB_SET_COLOR(elm, RBColor::RB_BLACK);
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}
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr T* RB_REMOVE(RBHead<T>& head, T* elm) {
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T* child = nullptr;
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T* parent = nullptr;
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T* old = elm;
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RBColor color = RBColor::RB_BLACK;
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if (RB_LEFT(elm) == nullptr) {
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child = RB_RIGHT(elm);
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} else if (RB_RIGHT(elm) == nullptr) {
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child = RB_LEFT(elm);
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} else {
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T* left;
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elm = RB_RIGHT(elm);
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while ((left = RB_LEFT(elm)) != nullptr) {
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elm = left;
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}
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child = RB_RIGHT(elm);
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parent = RB_PARENT(elm);
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color = RB_COLOR(elm);
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if (child) {
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RB_SET_PARENT(child, parent);
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}
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if (parent) {
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if (RB_LEFT(parent) == elm) {
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RB_SET_LEFT(parent, child);
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} else {
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RB_SET_RIGHT(parent, child);
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}
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} else {
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head.SetRoot(child);
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}
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if (RB_PARENT(elm) == old) {
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parent = elm;
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}
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elm->SetRBEntry(old->GetRBEntry());
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if (RB_PARENT(old)) {
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if (RB_LEFT(RB_PARENT(old)) == old) {
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RB_SET_LEFT(RB_PARENT(old), elm);
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} else {
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RB_SET_RIGHT(RB_PARENT(old), elm);
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}
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} else {
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head.SetRoot(elm);
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}
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RB_SET_PARENT(RB_LEFT(old), elm);
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if (RB_RIGHT(old)) {
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RB_SET_PARENT(RB_RIGHT(old), elm);
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}
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if (parent) {
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left = parent;
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}
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if (color == RBColor::RB_BLACK) {
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RB_REMOVE_COLOR(head, parent, child);
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}
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return old;
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}
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parent = RB_PARENT(elm);
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color = RB_COLOR(elm);
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if (child) {
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RB_SET_PARENT(child, parent);
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}
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if (parent) {
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if (RB_LEFT(parent) == elm) {
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RB_SET_LEFT(parent, child);
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} else {
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RB_SET_RIGHT(parent, child);
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}
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} else {
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head.SetRoot(child);
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}
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if (color == RBColor::RB_BLACK) {
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RB_REMOVE_COLOR(head, parent, child);
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}
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return old;
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}
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template <typename T>
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requires HasRBEntry<T>
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constexpr void RB_INSERT_COLOR(RBHead<T>& head, T* elm) {
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T *parent = nullptr, *tmp = nullptr;
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while ((parent = RB_PARENT(elm)) != nullptr && RB_IS_RED(parent)) {
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T* gparent = RB_PARENT(parent);
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if (parent == RB_LEFT(gparent)) {
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tmp = RB_RIGHT(gparent);
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if (tmp && RB_IS_RED(tmp)) {
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RB_SET_COLOR(tmp, RBColor::RB_BLACK);
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RB_SET_BLACKRED(parent, gparent);
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elm = gparent;
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continue;
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}
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if (RB_RIGHT(parent) == elm) {
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RB_ROTATE_LEFT(head, parent, tmp);
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tmp = parent;
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parent = elm;
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elm = tmp;
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}
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RB_SET_BLACKRED(parent, gparent);
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RB_ROTATE_RIGHT(head, gparent, tmp);
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} else {
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tmp = RB_LEFT(gparent);
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if (tmp && RB_IS_RED(tmp)) {
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RB_SET_COLOR(tmp, RBColor::RB_BLACK);
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RB_SET_BLACKRED(parent, gparent);
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elm = gparent;
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continue;
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}
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if (RB_LEFT(parent) == elm) {
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RB_ROTATE_RIGHT(head, parent, tmp);
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tmp = parent;
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parent = elm;
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elm = tmp;
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}
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RB_SET_BLACKRED(parent, gparent);
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RB_ROTATE_LEFT(head, gparent, tmp);
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}
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}
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RB_SET_COLOR(head.Root(), RBColor::RB_BLACK);
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}
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template <typename T, typename Compare>
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requires HasRBEntry<T>
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constexpr T* RB_INSERT(RBHead<T>& head, T* elm, Compare cmp) {
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T* parent = nullptr;
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T* tmp = head.Root();
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int comp = 0;
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while (tmp) {
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parent = tmp;
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comp = cmp(elm, parent);
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if (comp < 0) {
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tmp = RB_LEFT(tmp);
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} else if (comp > 0) {
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tmp = RB_RIGHT(tmp);
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} else {
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return tmp;
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}
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}
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RB_SET(elm, parent);
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if (parent != nullptr) {
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if (comp < 0) {
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RB_SET_LEFT(parent, elm);
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} else {
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RB_SET_RIGHT(parent, elm);
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}
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} else {
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head.SetRoot(elm);
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}
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RB_INSERT_COLOR(head, elm);
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return nullptr;
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}
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template <typename T, typename Compare>
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requires HasRBEntry<T>
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constexpr T* RB_FIND(RBHead<T>& head, T* elm, Compare cmp) {
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T* tmp = head.Root();
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while (tmp) {
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const int comp = cmp(elm, tmp);
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if (comp < 0) {
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tmp = RB_LEFT(tmp);
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|
} else if (comp > 0) {
|
|
tmp = RB_RIGHT(tmp);
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename T, typename Compare>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_NFIND(RBHead<T>& head, T* elm, Compare cmp) {
|
|
T* tmp = head.Root();
|
|
T* res = nullptr;
|
|
|
|
while (tmp) {
|
|
const int comp = cmp(elm, tmp);
|
|
if (comp < 0) {
|
|
res = tmp;
|
|
tmp = RB_LEFT(tmp);
|
|
} else if (comp > 0) {
|
|
tmp = RB_RIGHT(tmp);
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
template <typename T, typename U, typename Compare>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_FIND_KEY(RBHead<T>& head, const U& key, Compare cmp) {
|
|
T* tmp = head.Root();
|
|
|
|
while (tmp) {
|
|
const int comp = cmp(key, tmp);
|
|
if (comp < 0) {
|
|
tmp = RB_LEFT(tmp);
|
|
} else if (comp > 0) {
|
|
tmp = RB_RIGHT(tmp);
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename T, typename U, typename Compare>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_NFIND_KEY(RBHead<T>& head, const U& key, Compare cmp) {
|
|
T* tmp = head.Root();
|
|
T* res = nullptr;
|
|
|
|
while (tmp) {
|
|
const int comp = cmp(key, tmp);
|
|
if (comp < 0) {
|
|
res = tmp;
|
|
tmp = RB_LEFT(tmp);
|
|
} else if (comp > 0) {
|
|
tmp = RB_RIGHT(tmp);
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
template <typename T, typename Compare>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_FIND_EXISTING(RBHead<T>& head, T* elm, Compare cmp) {
|
|
T* tmp = head.Root();
|
|
|
|
while (true) {
|
|
const int comp = cmp(elm, tmp);
|
|
if (comp < 0) {
|
|
tmp = RB_LEFT(tmp);
|
|
} else if (comp > 0) {
|
|
tmp = RB_RIGHT(tmp);
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
}
|
|
|
|
template <typename T, typename U, typename Compare>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_FIND_EXISTING_KEY(RBHead<T>& head, const U& key, Compare cmp) {
|
|
T* tmp = head.Root();
|
|
|
|
while (true) {
|
|
const int comp = cmp(key, tmp);
|
|
if (comp < 0) {
|
|
tmp = RB_LEFT(tmp);
|
|
} else if (comp > 0) {
|
|
tmp = RB_RIGHT(tmp);
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
}
|
|
|
|
template <typename T>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_NEXT(T* elm) {
|
|
if (RB_RIGHT(elm)) {
|
|
elm = RB_RIGHT(elm);
|
|
while (RB_LEFT(elm)) {
|
|
elm = RB_LEFT(elm);
|
|
}
|
|
} else {
|
|
if (RB_PARENT(elm) && (elm == RB_LEFT(RB_PARENT(elm)))) {
|
|
elm = RB_PARENT(elm);
|
|
} else {
|
|
while (RB_PARENT(elm) && (elm == RB_RIGHT(RB_PARENT(elm)))) {
|
|
elm = RB_PARENT(elm);
|
|
}
|
|
elm = RB_PARENT(elm);
|
|
}
|
|
}
|
|
return elm;
|
|
}
|
|
|
|
template <typename T>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_PREV(T* elm) {
|
|
if (RB_LEFT(elm)) {
|
|
elm = RB_LEFT(elm);
|
|
while (RB_RIGHT(elm)) {
|
|
elm = RB_RIGHT(elm);
|
|
}
|
|
} else {
|
|
if (RB_PARENT(elm) && (elm == RB_RIGHT(RB_PARENT(elm)))) {
|
|
elm = RB_PARENT(elm);
|
|
} else {
|
|
while (RB_PARENT(elm) && (elm == RB_LEFT(RB_PARENT(elm)))) {
|
|
elm = RB_PARENT(elm);
|
|
}
|
|
elm = RB_PARENT(elm);
|
|
}
|
|
}
|
|
return elm;
|
|
}
|
|
|
|
template <typename T>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_MIN(RBHead<T>& head) {
|
|
T* tmp = head.Root();
|
|
T* parent = nullptr;
|
|
|
|
while (tmp) {
|
|
parent = tmp;
|
|
tmp = RB_LEFT(tmp);
|
|
}
|
|
|
|
return parent;
|
|
}
|
|
|
|
template <typename T>
|
|
requires HasRBEntry<T>
|
|
constexpr T* RB_MAX(RBHead<T>& head) {
|
|
T* tmp = head.Root();
|
|
T* parent = nullptr;
|
|
|
|
while (tmp) {
|
|
parent = tmp;
|
|
tmp = RB_RIGHT(tmp);
|
|
}
|
|
|
|
return parent;
|
|
}
|
|
|
|
} // namespace Common::freebsd
|