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#ifndef TRIE_TRIE_HPP
#define TRIE_TRIE_HPP #include <algorithm> #include <cassert> #include <string> template <typename Object, typename Key> class Trie { public: Trie() : node{nullptr}, size_{0} { } Trie(const Trie &rhs) : node(rhs.node ? new Node(*rhs.node) : nullptr), size_{rhs.size_} { } Trie(Trie &&trie) : Trie() { swap(*this, trie); } friend void swap(Trie &lhs, Trie &rhs) { using std::swap; swap(lhs.node, rhs.node); swap(lhs.size_, rhs.size_); } ~Trie() { delete node; } Trie & operator=(Trie rhs) { swap(*this, rhs); return *this; } Trie & insert(const std::string &key, const Object &obj) { recursive_insert(node, key.c_str(), obj); return *this; } std::size_t size() const { return size_; } template <typename Visitor> const Trie & visit(const std::string &key, const Visitor &visitor) const { recursive_visit(node, key.c_str(), visitor); return *this; } private: struct Node { Node() : node{}, object{}, hasObject{false} { } Node(const Object &value) : node{}, object{value}, hasObject{true} { } Node(const Node &rhs) : object{rhs.object}, hasObject{rhs.hasObject} { for (std::size_t i=0; i<Key::size(); ++i) { node[i] = (rhs.node[i]) ? new Node(*rhs.node[i]) : nullptr; } } ~Node() { for (std::size_t i=0; i<Key::size(); ++i) { delete node[i]; } } Node *node[Key::size()]; Object object; bool hasObject; }; void recursive_insert(Node *&root, const char *c, const Object &value) { if (!root) { root = new Node(); } if (*c) { std::size_t key = Key::map(*c); recursive_insert(root->node[key], c+1, value); } else { if (!root->hasObject) { ++size_; } root->object = value; root->hasObject = true; } } template <typename Visitor> void recursive_visit(Node *root, const char *c, const Visitor &visitor) const { if (!root) { return; } if (c && *c) { std::size_t key = Key::map(*c); recursive_visit(root->node[key], c+1, visitor); } else { if (root->hasObject) { visitor(root->object); } for (std::size_t i=0; i<Key::size(); ++i) { recursive_visit(root->node[i], nullptr, visitor); } } } // // Aufgabe 9: Navigieren in Tries II // public: class Pointer { public: Pointer(Node *node = nullptr) : node(node) { } bool defined() const { return node!=nullptr; } bool exists() const { assert(defined()); return node->hasObject; } bool canDescendAt(char c) const { assert(defined()); return node->node[Key::map(c)] != nullptr; } bool descend(char c) { assert(defined()); node = node->node[Key::map(c)]; return defined(); } Object & operator*() { assert(exists()); return node->object; } Object operator*() const { assert(exists()); return node->object; } bool operator!=(const Pointer &other) const { return node != other.node; } class Iterator { public: Iterator(Pointer pointer, std::size_t key = Key::size()) : pointer(pointer), key(key) { if (key<Key::size() && !pointer.canDescendAt(Key::unmap(key))) { ++*this; } } bool operator!=(const Iterator &other) const { if (key!=other.key) { return true; } return pointer != other.pointer; } Iterator & operator++() { assert(key<Key::size()); if (pointer.defined()) { for(++key; key<Key::size(); ++key) { if (pointer.canDescendAt(Key::unmap(key))) { break; } } } else { key = Key::size(); } return *this; } char operator*() const { return Key::unmap(key); } private: Pointer pointer; std::size_t key; }; Iterator begin() const { return Iterator(node, 0); } Iterator end() const { return Iterator(node); } private: Node *node; }; Node *node; std::size_t size_; Pointer descend() { return Pointer(node); } }; #endif // TRIE_TRIE_HPP |