Hash-table（用除法散列法实现）

关键字只支持int型，初学者版本
用链表解决冲突问题

#ifndef C11LEARN_HASHDIVISION_H
#define C11LEARN_HASHDIVISION_H
#include "Chain.h"
template<typename T>
class HashDivision
{
protected:int capacity;Chain<T>**array;
public:HashDivision(int capacity = 701);HashDivision(const HashDivision<T> &hashDivision);const HashDivision<T> & operator =(const HashDivision<T> &hashDivision);T& operator[](int key);const T operator[](int key) const;Chain<T>* search(int key);bool insert(Chain<T>* node);bool remove(Chain<T>* node);virtual ~HashDivision();protected:virtual int hashing(int index);void clear();void copy(const HashDivision<T> &hashDivision);
};
template<typename T>
HashDivision<T>::HashDivision(int capacity):capacity(capacity){array = new Chain<T>* [this->capacity];
}
template<typename T>
HashDivision<T>::~HashDivision(){clear();delete [] array;array = nullptr;
}
template<typename T>
void HashDivision<T>::clear()
{Chain<T>* current;Chain<T>* next;for (int i = 0; i < capacity; ++i) {current = array[i];while (current!= nullptr){next = current->next;delete current;current = next;}}
}
template<typename T>
HashDivision<T>::HashDivision(const HashDivision<T> &hashDivision){capacity = hashDivision.capacity;array = new Chain<T>* [capacity];copy(hashDivision);
}
template<typename T>
const HashDivision<T> & HashDivision<T>::operator =(const HashDivision<T> &hashDivision){if(this == &hashDivision) return *this;clear();delete [] array;capacity = hashDivision.capacity;array = new Chain<T>* [capacity];copy(hashDivision);return *this;
}
template<typename T>
void HashDivision<T>::copy(const HashDivision<T> &hashDivision){Chain<T>* current;Chain<T>* prev;for (int i = 0; i < capacity; ++i) {prev = nullptr;current = hashDivision.array[i];while (current!= nullptr){prev = current;current = current->next;}while (prev!= nullptr){Chain<T>* node = new Chain<T>();node->key = prev->key;node->value = prev->value;insert(node);prev = prev->prev;}}
}
template<typename T>
T& HashDivision<T>::operator[](int key){Chain<T>* node = search(key);if(node == nullptr){node = new Chain<T>();node->key = key;insert(node);}return node->value;
}
template<typename T>
const T HashDivision<T>::operator[](int key) const{Chain<T>* node = search(key);if(node == nullptr){throw "no find this key";}return node->value;
}
template<typename T>
Chain<T>* HashDivision<T>::search(int key)
{int hash_code = hashing(key);Chain<T>* current = array[hash_code];while (current!= nullptr && current->key != key){current =current->next;}return current;
}
template<typename T>
int HashDivision<T>::hashing(int index){return index % capacity;
}
template<typename T>
bool HashDivision<T>::insert(Chain<T>* node){if(node == nullptr) return false;int hash_code = hashing(node->key);Chain<T>* current = array[hash_code];if(current == nullptr){array[hash_code] = node;}else{node->next = current;current->prev = node;array[hash_code] = node;}return true;
}
template<typename T>
bool HashDivision<T>::remove(Chain<T>* node){if(node == nullptr) return false;if(node->prev == nullptr){int hash_code = hashing(node->key);array[hash_code] = node->next;}else{node->prev->next = node->next;if(node->next!= nullptr)node->next->prev = node->prev;}delete node;node = nullptr;return true;
}#endif //C11LEARN_HASHDIVISION_H

辅助类
Chain代码链接

测试代码

    HashDivision<string> hashDivision;hashDivision[2] = "hello";hashDivision[5] = "world";cout<<hashDivision[2]<<endl;cout<<hashDivision[5]<<endl;