264 lines
6.8 KiB
C++
264 lines
6.8 KiB
C++
#pragma once
|
|
|
|
//set
|
|
//implementation: red-black tree
|
|
//
|
|
//search: O(log n) average; O(log n) worst
|
|
//insert: O(log n) average; O(log n) worst
|
|
//remove: O(log n) average; O(log n) worst
|
|
//
|
|
//requirements:
|
|
// bool T::operator==(const T&) const;
|
|
// bool T::operator< (const T&) const;
|
|
|
|
#include <nall/utility.hpp>
|
|
#include <nall/vector.hpp>
|
|
|
|
namespace nall {
|
|
|
|
template<typename T> struct set {
|
|
struct node_t {
|
|
T value;
|
|
bool red = 1;
|
|
node_t* link[2] = {nullptr, nullptr};
|
|
node_t() = default;
|
|
node_t(const T& value) : value(value) {}
|
|
};
|
|
|
|
node_t* root = nullptr;
|
|
unsigned nodes = 0;
|
|
|
|
set() = default;
|
|
set(const set& source) { operator=(source); }
|
|
set(set&& source) { operator=(move(source)); }
|
|
set(std::initializer_list<T> list) { for(auto& value : list) insert(value); }
|
|
~set() { reset(); }
|
|
|
|
auto operator=(const set& source) -> set& {
|
|
reset();
|
|
copy(root, source.root);
|
|
nodes = source.nodes;
|
|
return *this;
|
|
}
|
|
|
|
auto operator=(set&& source) -> set& {
|
|
root = source.root;
|
|
nodes = source.nodes;
|
|
source.root = nullptr;
|
|
source.nodes = 0;
|
|
return *this;
|
|
}
|
|
|
|
auto size() const -> unsigned { return nodes; }
|
|
auto empty() const -> bool { return nodes == 0; }
|
|
|
|
auto reset() -> void {
|
|
reset(root);
|
|
nodes = 0;
|
|
}
|
|
|
|
auto find(const T& value) -> maybe<T&> {
|
|
if(node_t* node = find(root, value)) return node->value;
|
|
return nothing;
|
|
}
|
|
|
|
auto find(const T& value) const -> maybe<const T&> {
|
|
if(node_t* node = find(root, value)) return node->value;
|
|
return nothing;
|
|
}
|
|
|
|
auto insert(const T& value) -> maybe<T&> {
|
|
unsigned count = size();
|
|
node_t* v = insert(root, value);
|
|
root->red = 0;
|
|
if(size() == count) return nothing;
|
|
return v->value;
|
|
}
|
|
|
|
template<typename... P> auto insert(const T& value, P&&... p) -> bool {
|
|
bool result = insert(value);
|
|
insert(forward<P>(p)...) | result;
|
|
return result;
|
|
}
|
|
|
|
auto remove(const T& value) -> bool {
|
|
unsigned count = size();
|
|
bool done = 0;
|
|
remove(root, &value, done);
|
|
if(root) root->red = 0;
|
|
return size() < count;
|
|
}
|
|
|
|
template<typename... P> auto remove(const T& value, P&&... p) -> bool {
|
|
bool result = remove(value);
|
|
return remove(forward<P>(p)...) | result;
|
|
}
|
|
|
|
struct base_iterator {
|
|
auto operator!=(const base_iterator& source) const -> bool { return position != source.position; }
|
|
|
|
auto operator++() -> base_iterator& {
|
|
if(++position >= source.size()) { position = source.size(); return *this; }
|
|
|
|
if(stack.last()->link[1]) {
|
|
stack.append(stack.last()->link[1]);
|
|
while(stack.last()->link[0]) stack.append(stack.last()->link[0]);
|
|
} else {
|
|
node_t* child;
|
|
do child = stack.take();
|
|
while(child == stack.last()->link[1]);
|
|
}
|
|
|
|
return *this;
|
|
}
|
|
|
|
base_iterator(const set& source, unsigned position) : source(source), position(position) {
|
|
node_t* node = source.root;
|
|
while(node) {
|
|
stack.append(node);
|
|
node = node->link[0];
|
|
}
|
|
}
|
|
|
|
protected:
|
|
const set& source;
|
|
unsigned position;
|
|
vector<node_t*> stack;
|
|
};
|
|
|
|
struct iterator : base_iterator {
|
|
iterator(const set& source, unsigned position) : base_iterator(source, position) {}
|
|
auto operator*() const -> T& { return base_iterator::stack.last()->value; }
|
|
};
|
|
|
|
auto begin() -> iterator { return iterator(*this, 0); }
|
|
auto end() -> iterator { return iterator(*this, size()); }
|
|
|
|
struct const_iterator : base_iterator {
|
|
const_iterator(const set& source, unsigned position) : base_iterator(source, position) {}
|
|
auto operator*() const -> const T& { return base_iterator::stack.last()->value; }
|
|
};
|
|
|
|
auto begin() const -> const const_iterator { return const_iterator(*this, 0); }
|
|
auto end() const -> const const_iterator { return const_iterator(*this, size()); }
|
|
|
|
private:
|
|
auto reset(node_t*& node) -> void {
|
|
if(!node) return;
|
|
if(node->link[0]) reset(node->link[0]);
|
|
if(node->link[1]) reset(node->link[1]);
|
|
delete node;
|
|
node = nullptr;
|
|
}
|
|
|
|
auto copy(node_t*& target, const node_t* source) -> void {
|
|
if(!source) return;
|
|
target = new node_t(source->value);
|
|
target->red = source->red;
|
|
copy(target->link[0], source->link[0]);
|
|
copy(target->link[1], source->link[1]);
|
|
}
|
|
|
|
auto find(node_t* node, const T& value) const -> node_t* {
|
|
if(node == nullptr) return nullptr;
|
|
if(node->value == value) return node;
|
|
return find(node->link[node->value < value], value);
|
|
}
|
|
|
|
auto red(node_t* node) const -> bool { return node && node->red; }
|
|
auto black(node_t* node) const -> bool { return !red(node); }
|
|
|
|
auto rotate(node_t*& a, bool dir) -> void {
|
|
node_t*& b = a->link[!dir];
|
|
node_t*& c = b->link[dir];
|
|
a->red = 1, b->red = 0;
|
|
std::swap(a, b);
|
|
std::swap(b, c);
|
|
}
|
|
|
|
auto rotateTwice(node_t*& node, bool dir) -> void {
|
|
rotate(node->link[!dir], !dir);
|
|
rotate(node, dir);
|
|
}
|
|
|
|
auto insert(node_t*& node, const T& value) -> node_t* {
|
|
if(!node) { nodes++; node = new node_t(value); return node; }
|
|
if(node->value == value) { node->value = value; return node; } //prevent duplicate entries
|
|
|
|
bool dir = node->value < value;
|
|
node_t* v = insert(node->link[dir], value);
|
|
if(black(node->link[dir])) return v;
|
|
|
|
if(red(node->link[!dir])) {
|
|
node->red = 1;
|
|
node->link[0]->red = 0;
|
|
node->link[1]->red = 0;
|
|
} else if(red(node->link[dir]->link[dir])) {
|
|
rotate(node, !dir);
|
|
} else if(red(node->link[dir]->link[!dir])) {
|
|
rotateTwice(node, !dir);
|
|
}
|
|
|
|
return v;
|
|
}
|
|
|
|
auto balance(node_t*& node, bool dir, bool& done) -> void {
|
|
node_t* p = node;
|
|
node_t* s = node->link[!dir];
|
|
if(!s) return;
|
|
|
|
if(red(s)) {
|
|
rotate(node, dir);
|
|
s = p->link[!dir];
|
|
}
|
|
|
|
if(black(s->link[0]) && black(s->link[1])) {
|
|
if(red(p)) done = 1;
|
|
p->red = 0, s->red = 1;
|
|
} else {
|
|
bool save = p->red;
|
|
bool head = node == p;
|
|
|
|
if(red(s->link[!dir])) rotate(p, dir);
|
|
else rotateTwice(p, dir);
|
|
|
|
p->red = save;
|
|
p->link[0]->red = 0;
|
|
p->link[1]->red = 0;
|
|
|
|
if(head) node = p;
|
|
else node->link[dir] = p;
|
|
|
|
done = 1;
|
|
}
|
|
}
|
|
|
|
auto remove(node_t*& node, const T* value, bool& done) -> void {
|
|
if(!node) { done = 1; return; }
|
|
|
|
if(node->value == *value) {
|
|
if(!node->link[0] || !node->link[1]) {
|
|
node_t* save = node->link[!node->link[0]];
|
|
|
|
if(red(node)) done = 1;
|
|
else if(red(save)) save->red = 0, done = 1;
|
|
|
|
nodes--;
|
|
delete node;
|
|
node = save;
|
|
return;
|
|
} else {
|
|
node_t* heir = node->link[0];
|
|
while(heir->link[1]) heir = heir->link[1];
|
|
node->value = heir->value;
|
|
value = &heir->value;
|
|
}
|
|
}
|
|
|
|
bool dir = node->value < *value;
|
|
remove(node->link[dir], value, done);
|
|
if(!done) balance(node, dir, done);
|
|
}
|
|
};
|
|
|
|
}
|