Hash table (hash table) two probes

#pragma  once#include<iostream> #include <string>using namespace std;enum state{ empty,delete,exist,};template<class k, class v>struct hashtablenode{k _key; v _value;}; template<class k>struct __hashfunc  //default   functor {Size_t operator () that returns the hash key value keys ( Const k& key) {return key;}};/ /special String __hashfunc  functor Template<>struct __hashfunc<string>{size_t operator () (const &NBSP;STRING&AMP;&NBSP;STR) {size_t key = 0;for  (size_t i = 0; i  < str.size ();  i++) {key += str[i];} return key;}};/ /implementation of the hash table in the form of Key/value two-time detection template<class k, class v, class hashfunc = __ Hashfunc<k>>class hashtable{typedef hashtablenode<k, v> node;public: HashTable (size_t capacity = 10): _tables (new node[capacity]),  _size (0),  _staTES (New state[capacity]),  _capacity (capacity) {// memset  problematic   is initialized in bytes   But the second parameter value is Int//memset (_states, empty, sizeof (state)  * capacity);for  (size_t i  = 0; i < capacity; i++) {_states[i] = empty;}} ~hashtable () {if  (null != _tables) {delete[] _tables;_tables = null;} if  (null != _states) {delete[] _states;_states = null;}} Bool insert (const k& key, const v& value) {_CheckCapacity ();// Solve the getnextindex  conflict size_t index = _hashfunc (key);//  two-time detection    size_t  i = 1;while  (_states[index] == exist) {Index = _getnextindex (index,  i++);if  (index >= _capacity) {index = index % _capacity;}} _tables[index]._key = key;_tables[index]._value = value;_states[index] = exist;_size++;return true;} Node* find (Const k& key) {size_t index = _hashfunc (key); Size_t start  = index;size_t i = 1;//  presence   or   deleted   Two status while  (_states[index]  != empty) {if  (_tables[index]._key == key) {if  (_states[index] == exist ) {Return index;} else //  is removed  delete{return -1;}} Index = _getnextindex (index, i++);if  (index >= _capacity) {index =  index % _capacity;}   Because there is a fill factor   100%   does not appear full-full and key! =_key  the condition that causes the death cycle}return -1;} Bool remove (Const k& key) {int index = find (key);if  (index !=  -1) {_states[index] = delete;--_size;return true;} Return false;}   Two probes calculate the storage position Size_t _hashfunc (Const k& key) {HASHFUNC&NBSP;HF;RETURN&NBSP;HF (key)  % _capacity; //   Imitation function hf () &nbsP;}     Hash conflict when   get the next index can take advantage of the value of the previous index   This can be efficient   such as  string's index calculation is more time-consuming size_t  _getnextindex (size_t prev, size_t i) {return prev + 2 * i -  1;} Void print () {for  (size_t i = 0; i < _capacity; i++) {if  (_ states[i] == exist) {cout << i <<  "EXIST:"  << _tables [i]._key <<  "-------" &NBSP;&LT;&LT;&NBSP;_TABLES[I]._VALUE&NBSP;&LT;&LT;&NBSP;ENDL;} else if  (_states[i] == delete) {cout << i <<  "DELETE:"  << _tables[i]._key <<  "-------"  << _tables[i]._value  << endl;} else{cout << i <<  "EMPTY:"  << _tables[i]._key <<   "-------"  << _tables[i]._value << endl;}}} Void swap (HASHTABLE&LT;K,&NBsp V,&NBSP;HASHFUNC&GT;&AMP;&NBSP;HT) {swap (_size, ht._size); swap (_states, ht._states); Swap (_tables,  ht._tables); swap (_capacity, ht._capacity);} Protected:void _checkcapacity ()  //  expansion {//  Dynamic   Scalable//  efficient hash table The load factor is probably 0.7-0.8 better if   (10 * _size / _capacity >= 7)   // _size/_capacity for 0   Because all are plastic   so multiply 10//  to guarantee load factor within 0.7 {hashtable<k, v, hashfunc> tmp (2 * _ capacity);for  (size_t i = 0; i < _capacity; i++) {if  (_states[i ] == exist) {tmp. Insert (_tables[i]._key, _tables[i]._value);}} Swap (TMP);}} protected:node* _tables; state* _states;//Status Table size_t _size;size_t _capacity;};

Hash table (hash table) two probes