用C++实现一个哈希桶（插入，删除，寻找）

来源：互联网发布：windows安装器安装win7 编辑：程序博客网时间：2024/06/05 18:56
#include<iostream>#include<vector>#include<string>using namespace std;struct DefaultHashFuncString   //构造仿函数{size_t operator()(const string & key){size_t ret = 0;for (size_t i = 0; i < key.size(); i++){ret += key[i];}return ret;}};template<class K>struct DefaultHashFunc  //构造仿函数{size_t operator()(const K & key){return key;}};template<class K,class V>struct HashTableNode  //结点结构体{K _key;V _value;HashTableNode *_next;};template<class K, class V, class HashFunc = DefaultHashFunc<K>>class HashTable{typedef HashTableNode<K,V> Node;public:HashTable(size_t size = 10):_size(0){_table.resize(size);}~HashTable(){for (size_t i = 0; i < _table.size(); i++){Node *cur = _table[i];while (cur){Node* tmp = cur;cur = cur->_next;delete tmp;}}_size = 0;}public:void Insert(const K &key,const V& value) //插入{_CheckCapacity();size_t index = HashFun(key);Node *cur = _table[index];if (cur){while (cur->_next){cur = cur->_next;}cur->_next = new Node;cur = cur->_next;cur->_key = key;cur->_value = value;cur->_next = NULL;}else{_table[index] = new Node;_table[index]->_key = key;_table[index]->_value = value;_table[index]->_next = NULL;}++_size;}Node * Find(const K& key)  //寻找{size_t index = HashFun(key);Node *cur = _table[index];while (cur){if (cur->_key == key){return cur;}cur = cur->_next;}return NULL;}bool Remove(const K& key)  //删除{size_t index = HashFun(key);Node *cur = _table[index];if (!cur){return false;}else if (cur->_next == NULL){delete cur;_table[i] = NULL;return true;}else{Node * prev = cur;cur = cur->_next;while (cur){if (cur->_key == key){Node tmp = cur;cur = cur->_next;prev->next = tmp->_next;return true;}}}}void Printf(){for (size_t i = 0; i < _table.size(); i++){printf("_table[%d]:", i);Node *cur = _table[i];while (cur){cout << cur->_key << "->";cur = cur->_next;}cout << "NULL"<<endl;}}protected:size_t HashFun(const K & key)  //计算index{return HashFunc()(key) % _table.size();}void _CheckCapacity()  //容量检查<span style="font-family: Arial, Helvetica, sans-serif;">（负载因子）</span>{if (_size >= _table.size()){size_t size = 2 * _size;HashTable<K,V>tmp;/* = new Node[size];*/tmp._table.resize(size);for (size_t i = 0; i < _table.size(); i++){Node *cur = _table[i];while (cur){tmp.Insert(cur->_key,cur->_value);cur = cur->_next;}}_table.swap(tmp._table);}}protected:vector<Node*> _table;size_t _size;};
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