CONTENTS
备注：
本读书笔记基于侯捷先生的《STL源码剖析》，截图和注释版权均属于原作者所有。
本读书笔记中的源码部分直接拷贝自SGI-STL，部分代码删除了头部的版权注释，但代码版权属于原作者。
小弟初看stl，很多代码都不是太懂，注释可能有很多错误，还请路过的各位大牛多多给予指导。
为了降低学习难度，作者这里换到了SGI-STL-2.91.57的源码来学习，代码下载地址为【 http://jjhou.boolan.com/jjwbooks-tass.htm 】
之前笔记了下【 维基百科中关于红黑树的介绍 】，这里笔记下STL中的代码实现，部分代码为了便于理解，使用了前面的图。
stl_tree.h:
//先定义了红黑树中颜色的类型和【红】【黑】的值，便于后面进行判断。
typedef bool __rb_tree_color_type;
const __rb_tree_color_type __rb_tree_red = false;
const __rb_tree_color_type __rb_tree_black = true;
//红黑树的节点类基类
struct __rb_tree_node_base
{
typedef __rb_tree_color_type color_type;
typedef __rb_tree_node_base* base_ptr;
color_type color; //该节点的颜色
base_ptr parent;//指向父节点的指针
base_ptr left;//指向左子结点的指针
base_ptr right;//指向右子节点的指针
//获取当前红黑树的最小值，注意该函数为静态函数，需要入参。
//二叉搜索树的最小值很好找，最左边的节点为最小值。
static base_ptr minimum(base_ptr x)
{
while (x->left != 0) x = x->left;
return x;
}
//获取当前红黑树的最大值，注意该函数为静态函数，需要入参。
//二叉搜索树的最大值很好找，最右边的节点为最大值。
static base_ptr maximum(base_ptr x)
{
while (x->right != 0) x = x->right;
return x;
}
};
//红黑树的节点类
template <class Value>
struct __rb_tree_node : public __rb_tree_node_base
{
typedef __rb_tree_node<Value>* link_type;
Value value_field;//节点储存的值
};
//红黑树iterator基类
struct __rb_tree_base_iterator
{
typedef __rb_tree_node_base::base_ptr base_ptr;
typedef bidirectional_iterator_tag iterator_category;
typedef ptrdiff_t difference_type;
base_ptr node;//iterator指向的节点
void increment()//iterator递增函数，找到大于它的下一个节点。
{
if (node->right != 0) {//有右子树，那么就是右子树的最小值，即右子树的最左边的值
node = node->right;
while (node->left != 0)
node = node->left;
}
else {//没有右子树，就一直上溯，找到该节点所属的【整棵左子树】的父节点。
base_ptr y = node->parent;
while (node == y->right) {
node = y;
y = y->parent;
}
if (node->right != y) //循环退出之后，如果是因为找到了父子树的话，就把iterator指向的node指向该父子树。
node = y;
}
}
void decrement()//iterator递减函数，找到小于它的下一个节点。
{
if (node->color == __rb_tree_red &&
node->parent->parent == node)
node = node->right;
else if (node->left != 0) {//有左子树，那么就是左子树的最大值，即左子树的最右边的值
base_ptr y = node->left;
while (y->right != 0)
y = y->right;
node = y;
}
else {//没有左子树，就一直上溯，找到该节点所属的【整棵右子树】的父节点。
base_ptr y = node->parent;
while (node == y->left) {
node = y;
y = y->parent;
}
node = y;
}
}
};
increment和decrement的一些操作比较复杂，这里先画张图，将STL中的节点的关系标下，如下图：
//红黑树iterator类
template <class Value, class Ref, class Ptr>
struct __rb_tree_iterator : public __rb_tree_base_iterator
{
typedef Value value_type;
typedef Ref reference;
typedef Ptr pointer;
typedef __rb_tree_iterator<Value, Value&, Value*> iterator;
typedef __rb_tree_iterator<Value, const Value&, const Value*> const_iterator;
typedef __rb_tree_iterator<Value, Ref, Ptr> self;
typedef __rb_tree_node<Value>* link_type;
//各种构造函数。
__rb_tree_iterator() {}
__rb_tree_iterator(link_type x) { node = x; }
__rb_tree_iterator(const iterator& it) { node = it.node; }
//对iterator进行解引用，返回的是iterator指向的节点的存储的值。
reference operator*() const { return link_type(node)->value_field; }
#ifndef __SGI_STL_NO_ARROW_OPERATOR
pointer operator->() const { return &(operator*()); }
#endif /* __SGI_STL_NO_ARROW_OPERATOR */
//递增运算符，实际上调用的是iterator的increment方法。
self& operator++() { increment(); return *this; }
self operator++(int) {
self tmp = *this;
increment();
return tmp;
}
//递减运算符，实际上调用的是iterator的decrement方法。
self& operator--() { decrement(); return *this; }
self operator--(int) {
self tmp = *this;
decrement();
return tmp;
}
};
//判断两个iterator是否相等
inline bool operator==(const __rb_tree_base_iterator& x,
const __rb_tree_base_iterator& y) {
return x.node == y.node;
}
//判断两个iterator是否不等
inline bool operator!=(const __rb_tree_base_iterator& x,
const __rb_tree_base_iterator& y) {
return x.node != y.node;
}
#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION
//返回iterator的类型
inline bidirectional_iterator_tag
iterator_category(const __rb_tree_base_iterator&) {
return bidirectional_iterator_tag();
}
inline __rb_tree_base_iterator::difference_type*
distance_type(const __rb_tree_base_iterator&) {
return (__rb_tree_base_iterator::difference_type*) 0;
}
template <class Value, class Ref, class Ptr>
inline Value* value_type(const __rb_tree_iterator<Value, Ref, Ptr>&) {
return (Value*) 0;
}
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
左旋：
inline void
__rb_tree_rotate_left(__rb_tree_node_base* x, __rb_tree_node_base*& root)
{
__rb_tree_node_base* y = x->right;
x->right = y->left;
if (y->left !=0)
y->left->parent = x;
y->parent = x->parent;
if (x == root)
root = y;
else if (x == x->parent->left)
x->parent->left = y;
else
x->parent->right = y;
y->left = x;
x->parent = y;
}
如下图：
右旋：
inline void
__rb_tree_rotate_right(__rb_tree_node_base* x, __rb_tree_node_base*& root)
{
__rb_tree_node_base* y = x->left;
x->left = y->right;
if (y->right != 0)
y->right->parent = x;
y->parent = x->parent;
if (x == root)
root = y;
else if (x == x->parent->right)
x->parent->right = y;
else
x->parent->left = y;
y->right = x;
x->parent = y;
}
如下图：
//节点X插入树中之后，红黑树自平衡一次，参考插入操作部分笔记。
inline void
__rb_tree_rebalance(__rb_tree_node_base* x, __rb_tree_node_base*& root)
{
//首先默认令插入的节点的颜色为红色
x->color = __rb_tree_red;
//如果父节点为红色，参考情形3及之后情形
while (x != root && x->parent->color == __rb_tree_red)
{
//X的父节点P为G节点的左子结点。
if (x->parent == x->parent->parent->left) {
//y为G节点的右子节点，即P的兄弟节点，X的叔父节点。
__rb_tree_node_base* y = x->parent->parent->right;
if (y && y->color == __rb_tree_red) {
//情形3: 父节点P和叔父节点U二者都是红色
x->parent->color = __rb_tree_black;//那么P，U均改为黑色
y->color = __rb_tree_black;
x->parent->parent->color = __rb_tree_red;//G改为红色。
//将G认为是新加入的节点，重复判断。
x = x->parent->parent;
}
else {
//情形4: 父节点P是红色而叔父节点U是黑色。
if (x == x->parent->right)
{ //新节点N是其父节点P的右子节点（右左情况），先左旋至左左情况。
x = x->parent;
__rb_tree_rotate_left(x, root);//左旋
}
//到了这里情况为：情形5: 父节点P是红色而叔父节点U是黑色，新节点N是其父节点的左子节点，而父节点P又是其父节点G的左子节点（左左情况）。
//直接使用情形5右旋一下即可。
x->parent->color = __rb_tree_black;//G节点变为黑色
x->parent->parent->color = __rb_tree_red;//A节点变为红色
__rb_tree_rotate_right(x->parent->parent, root);//右旋，注意这里的代码是先调整G，A节点颜色再右旋，作者自己画的图是先右旋在变颜色，实际效果是一样的。
}
}
else {//X的父节点P为G节点的右子结点。
//y为G节点的右子节点，即P的兄弟节点，X的叔父节点。
__rb_tree_node_base* y = x->parent->parent->left;
if (y && y->color == __rb_tree_red) {
//情形3: 父节点P和叔父节点U二者都是红色
x->parent->color = __rb_tree_black;
y->color = __rb_tree_black;
x->parent->parent->color = __rb_tree_red;
x = x->parent->parent;
}
else {
//情形4: 父节点P是红色而叔父节点U是黑色。
if (x == x->parent->left) {
//新节点N是其父节点P的左子节点（左右情况），先右旋至右右情况。
x = x->parent;
__rb_tree_rotate_right(x, root);
}
//到了这里情况为：情形5: 右右情况，直接使用情形5右旋一下即可。
x->parent->color = __rb_tree_black;
x->parent->parent->color = __rb_tree_red;
__rb_tree_rotate_left(x->parent->parent, root);
}
}
}
//while循环结束之后，只有两种情况：情形1（x == root）或者情形2（x->parent->color == __rb_tree_black），这里直接把root节点赋黑色即可。
root->color = __rb_tree_black;
}
//节点Z从树中删除之后，红黑树自平衡一次，参考删除操作部分笔记。
inline __rb_tree_node_base*
__rb_tree_rebalance_for_erase(__rb_tree_node_base* z,
__rb_tree_node_base*& root,
__rb_tree_node_base*& leftmost,
__rb_tree_node_base*& rightmost)
{
//如果要删除的节点Z没有子节点就把它删掉了，如果它有子节点，那么根据二叉树的规则，被删除的节点会被它的左子树中的最大元素【B】、或者在它的右子树中的最小元素【C】所替换。因此实际上删除的节点是它的左子树中的最大元素【B】、或者在它的右子树中的最小元素【C】。在本函数实现中，这里用的是右子树中的最小元素【C】所替换。
__rb_tree_node_base* y = z;//Y指向的是删除Z时实际要替换上去的节点。
__rb_tree_node_base* x = 0;//x指向的是删除Z时实际要替换上去的节点Y的子节点。
__rb_tree_node_base* x_parent = 0;
if (y->left == 0) // z has at most one non-null child. y == z.
x = y->right; // x might be null.
else
if (y->right == 0) // z has exactly one non-null child. y == z.
x = y->left; // x is not null.
else { // z has two non-null children. Set y to
y = y->right; // z's successor. x might be null.
while (y->left != 0)
y = y->left;
x = y->right;
//Y是Z的右子树的最小值，经过循环之后，Y没有左子结点了，X是Y的子节点。
}
// Y和Z不是同一个节点，那么二叉树删除的逻辑是用Y代替Z,用X代替Y，实际上删除的节点位置为Y位置而不是Z位置。
if (y != z) { // relink y in place of z. y is z's successor
z->left->parent = y;
y->left = z->left;
if (y != z->right) {
x_parent = y->parent;
if (x) x->parent = y->parent;
y->parent->left = x; // y must be a left child
y->right = z->right;
z->right->parent = y;
}
else
x_parent = y;
if (root == z)
root = y;
else if (z->parent->left == z)
z->parent->left = y;
else
z->parent->right = y;
y->parent = z->parent;
__STD::swap(y->color, z->color);
y = z;
// y now points to node to be actually deleted
}
else { // y == z
//Y和Z是同一个节点，说明Z只有一个子树X。直接用X替换掉Z即可，这里删除的位置是Z（Y）位置。
x_parent = y->parent;
if (x) x->parent = y->parent;
if (root == z)
root = x;
else
if (z->parent->left == z)
z->parent->left = x;
else
z->parent->right = x;
if (leftmost == z)
if (z->right == 0) // z->left must be null also
leftmost = z->parent;
// makes leftmost == header if z == root
else
leftmost = __rb_tree_node_base::minimum(x);
if (rightmost == z)
if (z->left == 0) // z->right must be null also
rightmost = z->parent;
// makes rightmost == header if z == root
else // x == z->left
rightmost = __rb_tree_node_base::maximum(x);
}
//由于删除的位置是Y位置，因此这里就要判断Y位置的颜色。
//注意这里的代码实现和维基百科的有些出入。
if (y->color != __rb_tree_red) { //Y:要删除的节点为黑色时，X：Y的子节点。x_parent：X的父节点。
while (x != root && (x == 0 || x->color == __rb_tree_black))
//x是左子结点
if (x == x_parent->left) {
//w：Y的兄弟节点，x的叔父节点。
__rb_tree_node_base* w = x_parent->right;
if (w->color == __rb_tree_red) {
//情形2: S是红色，处理时包含了情形4。
w->color = __rb_tree_black;//S变为黑色
x_parent->color = __rb_tree_red;//P变为红色
__rb_tree_rotate_left(x_parent, root);//左旋，作者自己画的图是先左旋在变颜色，实际效果是一样的。
w = x_parent->right;
}
//情形3: P、S、SL、SR都是黑色的。
if ((w->left == 0 || w->left->color == __rb_tree_black) &&
(w->right == 0 || w->right->color == __rb_tree_black)) {
w->color = __rb_tree_red;
x = x_parent;
x_parent = x_parent->parent;
} else {
//W的左子结点为红色，右子节点为黑色，
//情形5: S是黑色，SL是红色，SR是黑色，P颜色无所谓，而N是P的左子节点。
if (w->right == 0 || w->right->color == __rb_tree_black) {
if (w->left) w->left->color = __rb_tree_black;
w->color = __rb_tree_red;
__rb_tree_rotate_right(w, root);//右旋
w = x_parent->right;
}
//情形6: S是黑色，SR是红色，而N是P的左子节点，P颜色无所谓。
w->color = x_parent->color;//S和P颜色互换
x_parent->color = __rb_tree_black;
if (w->right) w->right->color = __rb_tree_black;//SR变黑色
__rb_tree_rotate_left(x_parent, root);//左旋
break;
}
} else { // same as above, with right <-> left.
__rb_tree_node_base* w = x_parent->left;
if (w->color == __rb_tree_red) {
w->color = __rb_tree_black;
x_parent->color = __rb_tree_red;
__rb_tree_rotate_right(x_parent, root);
w = x_parent->left;
}
if ((w->right == 0 || w->right->color == __rb_tree_black) &&
(w->left == 0 || w->left->color == __rb_tree_black)) {
w->color = __rb_tree_red;
x = x_parent;
x_parent = x_parent->parent;
} else {
if (w->left == 0 || w->left->color == __rb_tree_black) {
if (w->right) w->right->color = __rb_tree_black;
w->color = __rb_tree_red;
__rb_tree_rotate_left(w, root);
w = x_parent->left;
}
w->color = x_parent->color;
x_parent->color = __rb_tree_black;
if (w->left) w->left->color = __rb_tree_black;
__rb_tree_rotate_right(x_parent, root);
break;
}
}
//情形B：如果删除一个黑色节点，且它的子节点是红色。
//此时直接删掉该节点，让其子节点X顶替自己，颜色变黑色即可。
if (x) x->color = __rb_tree_black;
}
//情形A：如果删除一个红色节点。直接返回，什么都不做。
return y;
}
备注：以下代码只做了部分笔记，后续补全吧。
//红黑树的实现类
template <class Key, class Value, class KeyOfValue, class Compare,
class Alloc = alloc>
class rb_tree {
protected:
typedef void* void_pointer;
typedef __rb_tree_node_base* base_ptr;
typedef __rb_tree_node<Value> rb_tree_node;
typedef simple_alloc<rb_tree_node, Alloc> rb_tree_node_allocator;
typedef __rb_tree_color_type color_type;
public:
typedef Key key_type;
typedef Value value_type;
typedef value_type* pointer;
typedef const value_type* const_pointer;
typedef value_type& reference;
typedef const value_type& const_reference;
typedef rb_tree_node* link_type;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
protected:
//申请一个新的节点
link_type get_node() { return rb_tree_node_allocator::allocate(); }
//释放一个新的节点
void put_node(link_type p) { rb_tree_node_allocator::deallocate(p); }
//创建一个新的节点，节点值为X
link_type create_node(const value_type& x) {
link_type tmp = get_node();//首先申请内存
__STL_TRY {
construct(&tmp->value_field, x);//调用构造函数
}
__STL_UNWIND(put_node(tmp));
return tmp;
}
//克隆一个节点。
link_type clone_node(link_type x) {
link_type tmp = create_node(x->value_field);//先构造一个节点
tmp->color = x->color;//把颜色复制过来
tmp->left = 0;//左右子节点都为0
tmp->right = 0;
return tmp;
}
//删除一个节点。
void destroy_node(link_type p) {
destroy(&p->value_field);//先调用析构函数
put_node(p);//然后释放内存
}
protected:
size_type node_count; // keeps track of size of tree //树中节点的数量
link_type header; //特殊节点，指向树的最大，最小值，以及根节点。
Compare key_compare;//节点大小的比较方式
//返回树的根节点
link_type& root() const { return (link_type&) header->parent; }
//返回树的最左节点
link_type& leftmost() const { return (link_type&) header->left; }
//返回树的最右节点
link_type& rightmost() const { return (link_type&) header->right; }
//返回某个节点的左子结点
static link_type& left(link_type x) { return (link_type&)(x->left); }
//返回某个节点的右子结点
static link_type& right(link_type x) { return (link_type&)(x->right); }
//返回某个节点的父节点
static link_type& parent(link_type x) { return (link_type&)(x->parent); }
//返回某个节点的节点值的引用
static reference value(link_type x) { return x->value_field; }
static const Key& key(link_type x) { return KeyOfValue()(value(x)); }
//返回颜色的类型
static color_type& color(link_type x) { return (color_type&)(x->color); }
//返回各种引用
static link_type& left(base_ptr x) { return (link_type&)(x->left); }
static link_type& right(base_ptr x) { return (link_type&)(x->right); }
static link_type& parent(base_ptr x) { return (link_type&)(x->parent); }
static reference value(base_ptr x) { return ((link_type)x)->value_field; }
static const Key& key(base_ptr x) { return KeyOfValue()(value(link_type(x)));}
static color_type& color(base_ptr x) { return (color_type&)(link_type(x)->color); }
//获取当前红黑树的最小值，注意该函数为静态函数，需要入参。
static link_type minimum(link_type x) {
return (link_type) __rb_tree_node_base::minimum(x);
}
//获取当前红黑树的最大值，注意该函数为静态函数，需要入参。
static link_type maximum(link_type x) {
return (link_type) __rb_tree_node_base::maximum(x);
}
public:
//iterator的定义
typedef __rb_tree_iterator<value_type, reference, pointer> iterator;
typedef __rb_tree_iterator<value_type, const_reference, const_pointer>
const_iterator;
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
typedef reverse_iterator<const_iterator> const_reverse_iterator;
typedef reverse_iterator<iterator> reverse_iterator;
#else /* __STL_CLASS_PARTIAL_SPECIALIZATION */
typedef reverse_bidirectional_iterator<iterator, value_type, reference,
difference_type>
reverse_iterator;
typedef reverse_bidirectional_iterator<const_iterator, value_type,
const_reference, difference_type>
const_reverse_iterator;
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
private:
iterator __insert(base_ptr x, base_ptr y, const value_type& v);
link_type __copy(link_type x, link_type p);
void __erase(link_type x);
//红黑树的初始化
void init() {
//申请header的内存
header = get_node();
color(header) = __rb_tree_red; // used to distinguish header from
// root, in iterator.operator++
root() = 0;
leftmost() = header;//初始化时最左最右指向均为header
rightmost() = header;
}
public:
//构造函数
// allocation/deallocation
rb_tree(const Compare& comp = Compare())
: node_count(0), key_compare(comp) { init(); }
//拷贝构造函数
rb_tree(const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& x)
: node_count(0), key_compare(x.key_compare)
{
header = get_node();
color(header) = __rb_tree_red;
if (x.root() == 0) {
root() = 0;
leftmost() = header;
rightmost() = header;
}
else {
__STL_TRY {
root() = __copy(x.root(), header);
}
__STL_UNWIND(put_node(header));
leftmost() = minimum(root());
rightmost() = maximum(root());
}
node_count = x.node_count;
}
//析构函数
~rb_tree() {
clear();//释放树中所有节点
put_node(header);//释放header节点
}
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>&
operator=(const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& x);
public:
// accessors:
Compare key_comp() const { return key_compare; }
//返回起始节点。
iterator begin() { return leftmost(); }
const_iterator begin() const { return leftmost(); }
//返回最终节点，这里直接返回的header
iterator end() { return header; }
const_iterator end() const { return header; }
reverse_iterator rbegin() { return reverse_iterator(end()); }
const_reverse_iterator rbegin() const {
return const_reverse_iterator(end());
}
reverse_iterator rend() { return reverse_iterator(begin()); }
const_reverse_iterator rend() const {
return const_reverse_iterator(begin());
}
//判断树是否为空
bool empty() const { return node_count == 0; }
//返回树的节点的数目
size_type size() const { return node_count; }
//返回最大节点数目，由于树的节点时动态申请的，因此最大数量和内存有关。
size_type max_size() const { return size_type(-1); }
void swap(rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& t) {
__STD::swap(header, t.header);
__STD::swap(node_count, t.node_count);
__STD::swap(key_compare, t.key_compare);
}
public:
// insert/erase
pair<iterator,bool> insert_unique(const value_type& x);
iterator insert_equal(const value_type& x);
iterator insert_unique(iterator position, const value_type& x);
iterator insert_equal(iterator position, const value_type& x);
#ifdef __STL_MEMBER_TEMPLATES
template <class InputIterator>
void insert_unique(InputIterator first, InputIterator last);
template <class InputIterator>
void insert_equal(InputIterator first, InputIterator last);
#else /* __STL_MEMBER_TEMPLATES */
void insert_unique(const_iterator first, const_iterator last);
void insert_unique(const value_type* first, const value_type* last);
void insert_equal(const_iterator first, const_iterator last);
void insert_equal(const value_type* first, const value_type* last);
#endif /* __STL_MEMBER_TEMPLATES */
void erase(iterator position);
size_type erase(const key_type& x);
void erase(iterator first, iterator last);
void erase(const key_type* first, const key_type* last);
//清除树中的所有数据。将Header的指向重置为初始状态。
void clear() {
if (node_count != 0) {
__erase(root());
leftmost() = header;
root() = 0;
rightmost() = header;
node_count = 0;
}
}
public:
// set operations:
iterator find(const key_type& x);
const_iterator find(const key_type& x) const;
size_type count(const key_type& x) const;
iterator lower_bound(const key_type& x);
const_iterator lower_bound(const key_type& x) const;
iterator upper_bound(const key_type& x);
const_iterator upper_bound(const key_type& x) const;
pair<iterator,iterator> equal_range(const key_type& x);
pair<const_iterator, const_iterator> equal_range(const key_type& x) const;
public:
// Debugging.
bool __rb_verify() const;
};
//判断两个树是否相等。通过判断其中的节点是否相等来判断
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
inline bool operator==(const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& x,
const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& y) {
return x.size() == y.size() && equal(x.begin(), x.end(), y.begin());
}
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
inline bool operator<(const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& x,
const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& y) {
return lexicographical_compare(x.begin(), x.end(), y.begin(), y.end());
}
#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
inline void swap(rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& x,
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& y) {
x.swap(y);
}
#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */
//赋值构造函数，先将本地的节点清除掉，然后将传入的树复制一份，保存下来。
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>&
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::
operator=(const rb_tree<Key, Value, KeyOfValue, Compare, Alloc>& x) {
if (this != &x) {
// Note that Key may be a constant type.
clear();
node_count = 0;
key_compare = x.key_compare;
if (x.root() == 0) {
root() = 0;
leftmost() = header;
rightmost() = header;
}
else {
root() = __copy(x.root(), header);
leftmost() = minimum(root());
rightmost() = maximum(root());
node_count = x.node_count;
}
}
return *this;
}
//插入一个节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::
__insert(base_ptr x_, base_ptr y_, const Value& v) {
link_type x = (link_type) x_;
link_type y = (link_type) y_;
link_type z;
if (y == header || x != 0 || key_compare(KeyOfValue()(v), key(y))) {
z = create_node(v);
left(y) = z; // also makes leftmost() = z when y == header
if (y == header) {
root() = z;
rightmost() = z;
}
else if (y == leftmost())
leftmost() = z; // maintain leftmost() pointing to min node
}
else {
z = create_node(v);
right(y) = z;
if (y == rightmost())
rightmost() = z; // maintain rightmost() pointing to max node
}
parent(z) = y;
left(z) = 0;
right(z) = 0;
__rb_tree_rebalance(z, header->parent);
++node_count;
return iterator(z);
}
//插入一个节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::insert_equal(const Value& v)
{
link_type y = header;
link_type x = root();
while (x != 0) {
y = x;
x = key_compare(KeyOfValue()(v), key(x)) ? left(x) : right(x);
}
return __insert(x, y, v);
}
//插入一个唯一的节点，如果之前已经插入过，就返回已经存在的节点（返回为pair，第二个参数表示是否是新申请的还是之前存在的）
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
pair<typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator, bool>
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::insert_unique(const Value& v)
{
link_type y = header;
link_type x = root();
bool comp = true;
//先在树中查找一下，看下之前有没有插入过。
while (x != 0) {
y = x;
comp = key_compare(KeyOfValue()(v), key(x));
x = comp ? left(x) : right(x);
}
iterator j = iterator(y);
if (comp)
if (j == begin())
return pair<iterator,bool>(__insert(x, y, v), true);
else
--j;
if (key_compare(key(j.node), KeyOfValue()(v)))
return pair<iterator,bool>(__insert(x, y, v), true);
return pair<iterator,bool>(j, false);
}
template <class Key, class Val, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Val, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Val, KeyOfValue, Compare, Alloc>::insert_unique(iterator position,
const Val& v) {
if (position.node == header->left) // begin()
if (size() > 0 && key_compare(KeyOfValue()(v), key(position.node)))
return __insert(position.node, position.node, v);
// first argument just needs to be non-null
else
return insert_unique(v).first;
else if (position.node == header) // end()
if (key_compare(key(rightmost()), KeyOfValue()(v)))
return __insert(0, rightmost(), v);
else
return insert_unique(v).first;
else {
iterator before = position;
--before;
if (key_compare(key(before.node), KeyOfValue()(v))
&& key_compare(KeyOfValue()(v), key(position.node)))
if (right(before.node) == 0)
return __insert(0, before.node, v);
else
return __insert(position.node, position.node, v);
// first argument just needs to be non-null
else
return insert_unique(v).first;
}
}
template <class Key, class Val, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Val, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Val, KeyOfValue, Compare, Alloc>::insert_equal(iterator position,
const Val& v) {
if (position.node == header->left) // begin()
if (size() > 0 && key_compare(KeyOfValue()(v), key(position.node)))
return __insert(position.node, position.node, v);
// first argument just needs to be non-null
else
return insert_equal(v);
else if (position.node == header) // end()
if (!key_compare(KeyOfValue()(v), key(rightmost())))
return __insert(0, rightmost(), v);
else
return insert_equal(v);
else {
iterator before = position;
--before;
if (!key_compare(KeyOfValue()(v), key(before.node))
&& !key_compare(key(position.node), KeyOfValue()(v)))
if (right(before.node) == 0)
return __insert(0, before.node, v);
else
return __insert(position.node, position.node, v);
// first argument just needs to be non-null
else
return insert_equal(v);
}
}
#ifdef __STL_MEMBER_TEMPLATES
template <class K, class V, class KoV, class Cmp, class Al> template<class II>
void rb_tree<K, V, KoV, Cmp, Al>::insert_equal(II first, II last) {
for ( ; first != last; ++first)
insert_equal(*first);
}
template <class K, class V, class KoV, class Cmp, class Al> template<class II>
void rb_tree<K, V, KoV, Cmp, Al>::insert_unique(II first, II last) {
for ( ; first != last; ++first)
insert_unique(*first);
}
#else /* __STL_MEMBER_TEMPLATES */
template <class K, class V, class KoV, class Cmp, class Al>
void
rb_tree<K, V, KoV, Cmp, Al>::insert_equal(const V* first, const V* last) {
for ( ; first != last; ++first)
insert_equal(*first);
}
template <class K, class V, class KoV, class Cmp, class Al>
void
rb_tree<K, V, KoV, Cmp, Al>::insert_equal(const_iterator first,
const_iterator last) {
for ( ; first != last; ++first)
insert_equal(*first);
}
template <class K, class V, class KoV, class Cmp, class A>
void
rb_tree<K, V, KoV, Cmp, A>::insert_unique(const V* first, const V* last) {
for ( ; first != last; ++first)
insert_unique(*first);
}
template <class K, class V, class KoV, class Cmp, class A>
void
rb_tree<K, V, KoV, Cmp, A>::insert_unique(const_iterator first,
const_iterator last) {
for ( ; first != last; ++first)
insert_unique(*first);
}
#endif /* __STL_MEMBER_TEMPLATES */
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
inline void
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::erase(iterator position) {
link_type y = (link_type) __rb_tree_rebalance_for_erase(position.node,
header->parent,
header->left,
header->right);
destroy_node(y);
--node_count;
}
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::size_type
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::erase(const Key& x) {
pair<iterator,iterator> p = equal_range(x);
size_type n = 0;
distance(p.first, p.second, n);
erase(p.first, p.second);
return n;
}
template <class K, class V, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<K, V, KeyOfValue, Compare, Alloc>::link_type
rb_tree<K, V, KeyOfValue, Compare, Alloc>::__copy(link_type x, link_type p) {
// structural copy. x and p must be non-null.
link_type top = clone_node(x);
top->parent = p;
__STL_TRY {
if (x->right)
top->right = __copy(right(x), top);
p = top;
x = left(x);
while (x != 0) {
link_type y = clone_node(x);
p->left = y;
y->parent = p;
if (x->right)
y->right = __copy(right(x), y);
p = y;
x = left(x);
}
}
__STL_UNWIND(__erase(top));
return top;
}
//删除
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
void rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::__erase(link_type x) {
// erase without rebalancing
while (x != 0) {
__erase(right(x));
link_type y = left(x);
destroy_node(x);
x = y;
}
}
//删除iterator指向从first到last间的节点。
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
void rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::erase(iterator first,
iterator last) {
if (first == begin() && last == end())
clear();
else
while (first != last) erase(first++);
}
//删除节点值在first到last间的节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
void rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::erase(const Key* first,
const Key* last) {
while (first != last) erase(*first++);
}
//查找某个节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::find(const Key& k) {
link_type y = header; // Last node which is not less than k.
link_type x = root(); // Current node.
while (x != 0)
if (!key_compare(key(x), k))
y = x, x = left(x);
else
x = right(x);
iterator j = iterator(y);
return (j == end() || key_compare(k, key(j.node))) ? end() : j;
}
//查找某个节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::const_iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::find(const Key& k) const {
link_type y = header; /* Last node which is not less than k. */
link_type x = root(); /* Current node. */
while (x != 0) {
if (!key_compare(key(x), k))
y = x, x = left(x);
else
x = right(x);
}
const_iterator j = const_iterator(y);
return (j == end() || key_compare(k, key(j.node))) ? end() : j;
}
//返回返回小于K的最大节点和大于K的最小节点间的节点的数目
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::size_type
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::count(const Key& k) const {
pair<const_iterator, const_iterator> p = equal_range(k);
size_type n = 0;
distance(p.first, p.second, n);
return n;
}
//返回不大于K的最大的节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::lower_bound(const Key& k) {
link_type y = header; /* Last node which is not less than k. */
link_type x = root(); /* Current node. */
while (x != 0)
if (!key_compare(key(x), k))
y = x, x = left(x);
else
x = right(x);
return iterator(y);
}
//返回不大于K的最大的节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::const_iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::lower_bound(const Key& k) const {
link_type y = header; /* Last node which is not less than k. */
link_type x = root(); /* Current node. */
while (x != 0)
if (!key_compare(key(x), k))
y = x, x = left(x);
else
x = right(x);
return const_iterator(y);
}
//返回大于K的最小的节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::upper_bound(const Key& k) {
link_type y = header; /* Last node which is greater than k. */
link_type x = root(); /* Current node. */
while (x != 0) //一直找到树的最下面一层，才能找到大于K的【最小】的节点。
if (key_compare(k, key(x)))
y = x, x = left(x);//如果K小于x,那么就调到左子树上找更小的x。
else
x = right(x);//如果K大于x，那么转到右子树上继续找更大的x。
return iterator(y);
}
//返回大于K的最小的节点
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::const_iterator
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::upper_bound(const Key& k) const {
link_type y = header; /* Last node which is greater than k. */
link_type x = root(); /* Current node. */
while (x != 0)
if (key_compare(k, key(x)))
y = x, x = left(x);
else
x = right(x);
return const_iterator(y);
}
//返回小于K的最大节点对应的iterator和大于K的最小节点对应的iterator
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
inline pair<typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator,
typename rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::iterator>
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::equal_range(const Key& k) {
return pair<iterator, iterator>(lower_bound(k), upper_bound(k));
}
//返回小于K的最大节点对应的iterator和大于K的最小节点对应的iterator
template <class Key, class Value, class KoV, class Compare, class Alloc>
inline pair<typename rb_tree<Key, Value, KoV, Compare, Alloc>::const_iterator,
typename rb_tree<Key, Value, KoV, Compare, Alloc>::const_iterator>
rb_tree<Key, Value, KoV, Compare, Alloc>::equal_range(const Key& k) const {
return pair<const_iterator,const_iterator>(lower_bound(k), upper_bound(k));
}
//返回node到root间的黑色节点的数目
inline int __black_count(__rb_tree_node_base* node, __rb_tree_node_base* root)
{
if (node == 0)
return 0;
else {
int bc = node->color == __rb_tree_black ? 1 : 0;
if (node == root)
return bc;
else
return bc + __black_count(node->parent, root);
}
}
template <class Key, class Value, class KeyOfValue, class Compare, class Alloc>
bool
rb_tree<Key, Value, KeyOfValue, Compare, Alloc>::__rb_verify() const
{
if (node_count == 0 || begin() == end())
return node_count == 0 && begin() == end() &&
header->left == header && header->right == header;
int len = __black_count(leftmost(), root());
for (const_iterator it = begin(); it != end(); ++it) {
link_type x = (link_type) it.node;
link_type L = left(x);
link_type R = right(x);
if (x->color == __rb_tree_red)
if ((L && L->color == __rb_tree_red) ||
(R && R->color == __rb_tree_red))
return false;
if (L && key_compare(key(x), key(L)))
return false;
if (R && key_compare(key(R), key(x)))
return false;
if (!L && !R && __black_count(x, root()) != len)
return false;
}
if (leftmost() != __rb_tree_node_base::minimum(root()))
return false;
if (rightmost() != __rb_tree_node_base::maximum(root()))
return false;
return true;
}
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