mirror of
https://github.com/geode-sdk/geode.git
synced 2024-11-23 07:57:51 -05:00
347 lines
No EOL
12 KiB
C++
347 lines
No EOL
12 KiB
C++
#pragma once
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namespace geode::stl {
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struct _rb_tree_base {
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bool m_isblack;
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_rb_tree_base* m_parent;
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_rb_tree_base* m_left;
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_rb_tree_base* m_right;
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};
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template <typename T>
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struct _rb_tree_node : public _rb_tree_base {
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T m_value;
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};
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inline void _rb_tree_rotate_left(_rb_tree_base* const x, _rb_tree_base*& root);
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inline void _rb_tree_rotate_right(_rb_tree_base* const x, _rb_tree_base*& root);
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inline void _rb_insert_rebalance(
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bool const insert_left, _rb_tree_base* x, _rb_tree_base* p, _rb_tree_base& header
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);
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inline _rb_tree_base* _rb_increment(_rb_tree_base* __x) noexcept;
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inline _rb_tree_base* _rb_decrement(_rb_tree_base* __x) noexcept;
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inline _rb_tree_base* _rb_rebalance_for_erase(_rb_tree_base* const __z, _rb_tree_base& __header) noexcept;
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template <typename T>
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struct _rb_tree_iterator {
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typedef T value_type;
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typedef T& reference;
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typedef T* pointer;
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typedef _rb_tree_iterator<T> _Self;
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typedef _rb_tree_base* _Base_ptr;
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typedef _rb_tree_node<T>* _Link_type;
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_rb_tree_iterator() : m_node() {}
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explicit _rb_tree_iterator(_Base_ptr __x) noexcept : m_node(__x) {}
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reference operator*() const noexcept {
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return *static_cast<_Link_type>(m_node)->m_value;
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}
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pointer operator->() const noexcept {
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return static_cast<_Link_type>(m_node)->m_value;
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}
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_Self& operator++() noexcept {
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m_node = _rb_increment(m_node);
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return *this;
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}
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_Self operator++(int) noexcept {
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_Self __tmp = *this;
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m_node = _rb_increment(m_node);
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return __tmp;
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}
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_Self& operator--() noexcept {
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m_node = _rb_decrement(m_node);
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return *this;
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}
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_Self operator--(int) noexcept {
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_Self __tmp = *this;
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m_node = _rb_decrement(m_node);
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return __tmp;
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}
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bool operator==(_Self const& __x) const noexcept {
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return m_node == __x.m_node;
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}
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bool operator!=(_Self const& __x) const noexcept {
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return m_node != __x.m_node;
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}
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_Base_ptr m_node;
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};
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inline void _rb_tree_rotate_left(_rb_tree_base* const x, _rb_tree_base*& root) {
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_rb_tree_base* const y = x->m_right;
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x->m_right = y->m_left;
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if (y->m_left != 0) y->m_left->m_parent = x;
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y->m_parent = x->m_parent;
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if (x == root) root = y;
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else if (x == x->m_parent->m_left) x->m_parent->m_left = y;
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else x->m_parent->m_right = y;
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y->m_left = x;
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x->m_parent = y;
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}
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inline void _rb_tree_rotate_right(_rb_tree_base* const x, _rb_tree_base*& root) {
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_rb_tree_base* const y = x->m_left;
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x->m_left = y->m_right;
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if (y->m_right != 0) y->m_right->m_parent = x;
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y->m_parent = x->m_parent;
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if (x == root) root = y;
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else if (x == x->m_parent->m_right) x->m_parent->m_right = y;
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else x->m_parent->m_left = y;
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y->m_right = x;
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x->m_parent = y;
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}
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inline void _rb_insert_rebalance(
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bool const insert_left, _rb_tree_base* x, _rb_tree_base* p, _rb_tree_base& header
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) {
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_rb_tree_base*& root = header.m_parent;
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x->m_parent = p;
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x->m_left = 0;
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x->m_right = 0;
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x->m_isblack = false;
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if (insert_left) {
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p->m_left = x;
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if (p == &header) {
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header.m_parent = x;
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header.m_right = x;
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}
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else if (p == header.m_left) {
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header.m_left = x;
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}
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}
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else {
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p->m_right = x;
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if (p == header.m_right) {
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header.m_right = x;
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}
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}
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while (x != root && x->m_parent->m_isblack == false) {
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_rb_tree_base* const xpp = x->m_parent->m_parent;
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if (x->m_parent == xpp->m_left) {
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_rb_tree_base* const y = xpp->m_right;
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if (y && y->m_isblack == false) {
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x->m_parent->m_isblack = true;
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y->m_isblack = true;
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xpp->m_isblack = false;
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x = xpp;
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}
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else {
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if (x == x->m_parent->m_right) {
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x = x->m_parent;
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_rb_tree_rotate_left(x, root);
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}
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x->m_parent->m_isblack = true;
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xpp->m_isblack = false;
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_rb_tree_rotate_right(xpp, root);
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}
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}
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else {
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_rb_tree_base* const y = xpp->m_left;
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if (y && y->m_isblack == false) {
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x->m_parent->m_isblack = true;
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y->m_isblack = true;
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xpp->m_isblack = false;
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x = xpp;
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}
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else {
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if (x == x->m_parent->m_left) {
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x = x->m_parent;
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_rb_tree_rotate_right(x, root);
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}
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x->m_parent->m_isblack = true;
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xpp->m_isblack = false;
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_rb_tree_rotate_left(xpp, root);
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}
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}
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}
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root->m_isblack = true;
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}
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inline _rb_tree_base* _rb_increment(_rb_tree_base* __x) noexcept {
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if (__x->m_right != 0) {
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__x = __x->m_right;
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while (__x->m_left != 0)
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__x = __x->m_left;
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}
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else {
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_rb_tree_base* __y = __x->m_parent;
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while (__x == __y->m_right) {
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__x = __y;
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__y = __y->m_parent;
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}
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if (__x->m_right != __y) __x = __y;
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}
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return __x;
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}
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inline _rb_tree_base* _rb_decrement(_rb_tree_base* __x) noexcept {
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if (!__x->m_isblack && __x->m_parent->m_parent == __x) __x = __x->m_right;
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else if (__x->m_left != 0) {
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_rb_tree_base* __y = __x->m_left;
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while (__y->m_right != 0)
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__y = __y->m_right;
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__x = __y;
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}
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else {
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_rb_tree_base* __y = __x->m_parent;
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while (__x == __y->m_left) {
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__x = __y;
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__y = __y->m_parent;
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}
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__x = __y;
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}
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return __x;
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}
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inline _rb_tree_base* _rb_rebalance_for_erase(
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_rb_tree_base* const __z, _rb_tree_base& __header
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) noexcept {
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_rb_tree_base*& __root = __header.m_parent;
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_rb_tree_base*& __leftmost = __header.m_left;
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_rb_tree_base*& __rightmost = __header.m_right;
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_rb_tree_base* __y = __z;
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_rb_tree_base* __x = 0;
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_rb_tree_base* __x_parent = 0;
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if (__y->m_left == 0) // __z has at most one non-null child. y == z.
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__x = __y->m_right; // __x might be null.
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else if (__y->m_right == 0) // __z has exactly one non-null child. y == z.
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__x = __y->m_left; // __x is not null.
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else {
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// __z has two non-null children. Set __y to
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__y = __y->m_right; // __z's successor. __x might be null.
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while (__y->m_left != 0)
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__y = __y->m_left;
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__x = __y->m_right;
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}
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if (__y != __z) {
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// relink y in place of z. y is z's successor
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__z->m_left->m_parent = __y;
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__y->m_left = __z->m_left;
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if (__y != __z->m_right) {
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__x_parent = __y->m_parent;
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if (__x) __x->m_parent = __y->m_parent;
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__y->m_parent->m_left = __x; // __y must be a child of m_left
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__y->m_right = __z->m_right;
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__z->m_right->m_parent = __y;
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}
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else __x_parent = __y;
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if (__root == __z) __root = __y;
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else if (__z->m_parent->m_left == __z) __z->m_parent->m_left = __y;
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else __z->m_parent->m_right = __y;
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__y->m_parent = __z->m_parent;
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std::swap(__y->m_isblack, __z->m_isblack);
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__y = __z;
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// __y now points to node to be actually deleted
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}
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else { // __y == __z
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__x_parent = __y->m_parent;
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if (__x) __x->m_parent = __y->m_parent;
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if (__root == __z) __root = __x;
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else if (__z->m_parent->m_left == __z) __z->m_parent->m_left = __x;
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else __z->m_parent->m_right = __x;
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if (__leftmost == __z) {
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if (__z->m_right == 0) // __z->m_left must be null also
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__leftmost = __z->m_parent;
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// makes __leftmost == _M_header if __z == __root
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else {
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__leftmost = __x;
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while (__leftmost->m_left != 0)
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__leftmost = __leftmost->m_left;
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}
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}
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if (__rightmost == __z) {
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if (__z->m_left == 0) // __z->m_right must be null also
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__rightmost = __z->m_parent;
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// makes __rightmost == _M_header if __z == __root
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else { // __x == __z->m_left
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__rightmost = __x;
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while (__rightmost->m_right != 0)
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__rightmost = __rightmost->m_right;
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}
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}
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}
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if (__y->m_isblack != false) {
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while (__x != __root && (__x == 0 || __x->m_isblack))
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if (__x == __x_parent->m_left) {
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_rb_tree_base* __w = __x_parent->m_right;
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if (__w->m_isblack == false) {
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__w->m_isblack = true;
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__x_parent->m_isblack = false;
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_rb_tree_rotate_left(__x_parent, __root);
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__w = __x_parent->m_right;
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}
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if ((__w->m_left == 0 || __w->m_left->m_isblack == true) &&
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(__w->m_right == 0 || __w->m_right->m_isblack == true)) {
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__w->m_isblack = false;
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__x = __x_parent;
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__x_parent = __x_parent->m_parent;
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}
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else {
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if (__w->m_right == 0 || __w->m_right->m_isblack == true) {
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__w->m_left->m_isblack = true;
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__w->m_isblack = false;
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_rb_tree_rotate_right(__w, __root);
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__w = __x_parent->m_right;
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}
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__w->m_isblack = __x_parent->m_isblack;
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__x_parent->m_isblack = true;
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if (__w->m_right) __w->m_right->m_isblack = true;
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_rb_tree_rotate_left(__x_parent, __root);
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break;
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}
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}
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else {
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// same as above, with m_right <-> m_left.
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_rb_tree_base* __w = __x_parent->m_left;
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if (__w->m_isblack == false) {
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__w->m_isblack = true;
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__x_parent->m_isblack = false;
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_rb_tree_rotate_right(__x_parent, __root);
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__w = __x_parent->m_left;
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}
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if ((__w->m_right == 0 || __w->m_right->m_isblack == true) &&
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(__w->m_left == 0 || __w->m_left->m_isblack == true)) {
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__w->m_isblack = false;
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__x = __x_parent;
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__x_parent = __x_parent->m_parent;
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}
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else {
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if (__w->m_left == 0 || __w->m_left->m_isblack == true) {
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__w->m_right->m_isblack = true;
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__w->m_isblack = false;
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_rb_tree_rotate_left(__w, __root);
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__w = __x_parent->m_left;
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}
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__w->m_isblack = __x_parent->m_isblack;
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__x_parent->m_isblack = true;
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if (__w->m_left) __w->m_left->m_isblack = true;
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_rb_tree_rotate_right(__x_parent, __root);
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break;
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}
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}
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if (__x) __x->m_isblack = true;
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}
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return __y;
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}
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} |