HashMap
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#ifndef HASHMAP_H#define HASHMAP_H#include "stdlib.h"template<class K, class V> class HashMap;/*=============================================================================================== HashNode===============================================================================================*/template<class K, class V>class HashNode{friend class HashMap<K, V>;public: K& Key() { return key; } V& Value() { return value; } private: HashNode<K,V>* next; K key; V value;};/*=============================================================================================== HashMap ===============================================================================================*/template<class K, class V>class HashMap{public: typedef HashNode<K, V> Node; HashMap(int bucketSize = 16); ~HashMap(); void Clear(); V* GetPtr(K& key); bool Get(K& key, V& value); void Set(K& key, V& value); bool HasKey(K& key); void Remove(K& key); Node* First(); Node* Next(Node* it);private: Node** buckets; size_t bucketSize; size_t num; size_t GetHash(K& key);};/*===============================================================================================*/template<class K, class V>HashMap<K, V>::HashMap(int bucketSize_){ num = 0; bucketSize = bucketSize_; buckets = new Node*[bucketSize]; memset(buckets, 0, bucketSize * sizeof(Node*));}template<class K, class V>HashMap<K, V>::~HashMap(){ Clear(); delete[] buckets;}template<class K, class V>void HashMap<K, V>::Clear(){ size_ti; Node* node; Node* next; for (i = 0; i < bucketSize; i++) { for (node = buckets[i]; node; node = next) { next = node->next; delete node; } buckets[i] = NULL; } num = 0;}template<class K, class V>V* HashMap<K, V>::GetPtr(K& key){ size_t hash; Node* node; hash = GetHash(key); for (node = buckets[hash]; node; node = node->next) { if (node->key == key) return &node->value; } return NULL;}template<class K, class V>bool HashMap<K, V>::Get(K& key, V& value){ size_t hash; Node* node; hash = GetHash(key); for (node = buckets[hash]; node; node = node->next) { if (node->key == key) { value = node->value; return true; } } return false;}template<class K, class V>void HashMap<K, V>::Set(K& key, V& value){ size_t hash; Node* node; hash = GetHash(key); for (node = buckets[hash]; node; node = node->next) { if (node->key == key) { node->value = value; return; } } node = new Node; node->key = key; node->value = value; node->next = buckets[hash]; buckets[hash] = node; num++; // TODO resize if too small return;}template<class K, class V>bool HashMap<K, V>::HasKey(K& key){ if (GetPtr(key)) return true; return false;}template<class K, class V>void HashMap<K, V>::Remove(K& key){ size_t hash; Node* node; Node* next; Node** prev; hash = GetHash(key); prev = &buckets[hash]; for (node = buckets[hash]; node; node = next) { next = node->next; if (node->key == key) { *prev = next; delete node; num--; break; } prev = &node->next; } // TODO resize if too big}template<class K, class V>HashNode<K, V>* HashMap<K, V>::First(){ size_t i; for (i = 0; i < bucketSize; i++) { if (buckets[i]) return buckets[i]; } return NULL;}template<class K, class V>HashNode<K, V>* HashMap<K, V>::Next(Node* it){ size_t i; size_t hash; if (it->next) return it->next; hash = GetHash(it->key); for (i = hash + 1; i < bucketSize; i++) { if (buckets[i]) return buckets[i]; } return NULL;}template<class K, class V>size_t HashMap<K, V>::GetHash(K& key){ return Hash(key) % bucketSize;}#endif
