Hello, I was trying to create a Coalesced hash table by self teaching myself using various sources. I fixed most of the errors, but when i compile on either my visual C++ compiler or Dev -C++ both saids there is a undefine linker reference for the hash members in my Main.
#include <iostream>
using namespace std;
#include "Hash_file.h"
int main(void)
{
Hash_Map<int> Numbers(1);
Numbers.insert("one", 1);
cout<<Numbers.find("one");
cin.get();
return 0;
}I thought it had something to do with some error either in my header file or source file.. but im not sure now
#pragma once
#ifndef HASH_MAP
#define HASH_MAP
#include <string>
typedef struct Entry_t
{
void * Object;
Entry_t * next;
std::string Key;
int position;
}Entry;
template<class Map>
class Hash_Map
{
private :
Entry **Primary;
Entry **Secondary;
int Num;
size_t secondary_size;
public:
Hash_Map(const Hash_Map & Map_secondary);
// the default SuperFastHash comes from the included header file
Hash_Map( int num );
int insert(std::string key, Map map);
int deletion(std::string key);
bool isFull();
Map * find(std::string key);
int Secondaryinsert(std::string key, Map & map);
int Swap_Hash(int leftoff);
};
#endif#include "Hash_file.h"
#include <cstring>
//using Coalesced_hashing
//also will use incrementing for Resize
template< class Map>
Hash_Map<Map>::Hash_Map( const Hash_Map & Map_secondary)
{
Primary = Map_secondary.Primary;
Secondary = Map_secondary.Secondary;
Num = Map_secondary.Num;
}
template< class Map>
Hash_Map<Map>::Hash_Map( int num)
{
Num = num;
Primary = new Entry[num];
int i= 0;
while( i < Num)
{
Primary[Num] = NULL;
}
Secondary = NULL;
}
template< class Map>
int Hash_Map<Map>::insert(std::string key, Map map)
{
unsigned h = SuperFastHash(key.c_str(), strlen(key.c_str())) % Num;
if(Primary[h] == NULL)
{
Primary[h] = new Entry;
Primary[h]->Object = map;
Primary[h]->Key = key;
Primary[h]->position = h;
}
else
{
Entry * it;
int cursor = 0;
while(cursor < Num && Primary[cursor] != NULL)
++cursor;
if( cursor == Num)
return -1;
Primary[cursor] = new Entry;
Primary[cursor]->Object = map;
Primary[cursor]->Key = key;
Primary[cursor]->position = cursor;
it = Primary[h];
while(it->next != NULL)
it = it->next;
it->next = Primary[cursor];
}
return 0;
}
template< class Map>
Map * Hash_Map<Map>::find(std::string key)
{
unsigned h = SuperFastHash(key.c_str(),strlen(key.c_str())) % Num;
if ( Primary[h] != NULL ) {
Entry *it;
/* Search the chain at index h */
for ( it = Primary[h]; it != NULL; it = it->next ) {
if ( strcmp ( key.c_str(), it->Key.c_str() ) == 0 )
return (Map)it->Object;
}
}
return NULL;
}
template<class Map>
int Hash_Map<Map>::deletion(std::string key)
{
unsigned h = SuperFastHash(key.c_str(),strlen(key.c_str())) % Num;
if(Primary[h] != NULL)
{
if( strcmp ( key.c_str(), Primary[h]->Key.c_str() ) == 0)
{
delete Primary[h];
Primary[h] = NULL;
}
else
{
Entry * tempt1 = Primary[h]->next;
Entry * tempt2 = Primary[h];
while( tempt1 != NULL ) {
if ( strcmp ( key.c_str(), tempt1->Key.c_str() ) == 0 )
break;
tempt1 = tempt1->next;
tempt2 = tempt2->next;
}
tempt2->next = tempt1->next;
unsigned int P = tempt1->position;
delete Primary[P];
Primary[P] = NULL;
}
return 0;
}
return -1;
}
template< class Map>
bool Hash_Map<Map>:: isFull()
{
int cursor =0;
while(cursor < Num && Primary[cursor] != NULL)
++cursor;
if(cursor == Num )
return true;
return false;
}
template< class Map>
int Hash_Map<Map>::Secondaryinsert(std::string key, Map & map)
{
if(Secondary == NULL)
{
secondary_size = Num * 1.5;
Secondary = new Entry[secondary_size];
int i;
while( i < secondary_size )
{
Secondary[ i ] = NULL; ++i;
}
}
unsigned h = SuperFastHash(key.c_str(),strlen(key.c_str())) %secondary_size;
if(Secondary[h] == NULL)
{ Secondary[ h ] = new Entry;
Secondary[h]->Object = map;
Secondary[h]->Key = key;
Secondary[ h ]->position = h;
}
else
{
Entry * it;
int cursor = 0;
while(cursor < secondary_size&& Secondary[cursor] != NULL)
++cursor;
if( cursor == secondary_size)
return -1;
Secondary[cursor] = new Entry;
Secondary[cursor]->Object = map;
Secondary[cursor]->Key = key;
Secondary[cursor]->position = cursor;
it = Secondary[h];
while(it->next != NULL)
it = it->next;
it->next = Secondary[cursor];
}
return 0;
}
template< class Map>
int Hash_Map<Map>::Swap_Hash(int leftoff)
{
int Num_of_buckets_transfer = Num * .40;
int i;
int j;
if( leftoff != 0 )
for( i = leftoff, j = 0; j < Num_of_buckets_transfer; --i, j++)
{
unsigned int h;
h = SuperFastHash(Primary[i]->Key.c_str(),strlen(Primary[i]->Key.c_str())) % secondary_size;
if(Secondary[h] == NULL)
{
Secondary[h] = new Entry;
Secondary[h]->Key = Primary[i]->Key;
Secondary[h]->Object = Primary[i]->Object;
Secondary[ h ]->position = h;
}
else
{
Entry * it;
int cursor = 0;
while(cursor < secondary_size&& Secondary[cursor] != NULL)
++cursor;
if( cursor == secondary_size)
return -1;
Secondary[cursor] = new Entry;
Secondary[cursor]->Key = Primary[i]->Key;
Secondary[cursor]->Object = Primary[i]->Object;
Secondary[cursor]->position = cursor;
it = Secondary[h];
while(it->next != NULL)
it = it->next;
it->next = Secondary[cursor];
}
}
return leftoff;
}I tried to rebuild, and i made sure all the files were linked properly...
