suyu/src/common/tree.h

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