关于这个程序：
该程序用于实现HashTable。
问题如下：
1>正在链接... 1>HashTable.obj : error LNK2019: 无法解析的外部符号 "public: int __thiscall HashTable::remove(class Employee const &)" (?remove@?$HashTable@VEmployee@@@@ QAEHABVEmployee@@@Z)，该函数在函数_wmain中被引用
1>HashTable.obj : error LNK2019: 无法解析的外部符号 "public: int __thiscall HashTable::contains(class Employee const &)" (?contains@?$HashTable@VEmployee@@@@QAEHABVEmployee@@@Z)，该在符号函数 _wmain 中被引用
1>HashTable.obj : error LNK2019: 无法解析的外部符号 "public: void __thiscall HashTable::display(void)const " (?display@?$HashTable@VEmployee@@@@QBEXXZ)，该符号在函数_wmain中被引用 1>HashTable.obj : error LNK2019: 无法解析的外部符号 "public: int __thiscall HashTable::insert(class Employee const &)" (?insert@?$HashTable@VEmployee@@@@QAEHABVEmployee@@@Z )，该符号在函数_wmain中被引用
1>HashTable.obj : error LNK2019: 无法解析的外部符号 "public: __thiscall HashTable::HashTable(int)" (??0?$HashTable@VEmployee@@@@QAE@H@Z)，该符号在函数_wmain 中被引用
问题：
我不知道为什么会发生这种情况，因为我在 Hash.h 中给出了声明并在 Hash.cpp 中给出了定义。在发布这个问题之前，我已经通过互联网搜索了答案，但没有答案是我想要的。是有的原因我滥用模板时使用模板的一些特殊方法？
哈希.h：
#include "stdafx.h"
#include <iostream>
#include <vector>
#include <list>
#include <string>
#include <cstdlib>
#include <cmath>
#include <algorithm>
using namespace std;
template <class T>
class HashTable
{
public:
HashTable(int size = 101);
int insert(const T& x);
int remove(const T& x);
int contains(const T& x);
void make_empty();
void display()const;
private:
vector<list<T> > lists;
int currentSize;
int hash(const string& key);
int myhash(const T& x);
void rehash();
};
class Employee
{
public:
Employee(){}
Employee(const string n,int s=0):name(n),salary(s){ }
const string & getName()const { return name; }
bool operator == (const Employee &rhs) const
{
return getName() == rhs.getName();
}
bool operator != (const Employee &rhs) const
{
return !(*this == rhs);
}
friend ostream& operator <<(ostream& out,const Employee& e)
{
out<<"("<<e.name<<","<<e.salary<<") ";
return out;
}
private:
string name;
int salary;
};
哈希.cpp
#include "stdafx.h"
#include "Hash.h"
int nextPrime(const int n);
template <class T> HashTable<T>::HashTable(int size)
{
lists = vector<list<T> >(size);
currentSize = 0;
}
template <class T> int HashTable<T>::hash(const string& key)
{
int hashVal = 0;
int tableSize = lists.size();
for(int i=0;i<key.length();i++)
hashVal = 37*hashVal+key[i];
hashVal %= tableSize;
if(hashVal < 0)
hashVal += tableSize;
return hashVal;
}
template <class T> int HashTable<T>:: myhash(const T& x)
{
string key = x.getName();
return hash(key);
}
template <class T> int HashTable<T>::insert(const T& x)
{
list<T> &whichlist = lists[myhash(x)];
if(find(whichlist.begin(),whichlist.end(),x) != whichlist.end())
return 0;
whichlist.push_back(x);
currentSize = currentSize + 1;
if(currentSize > lists.size())
rehash();
return 1;
}
template <class T> int HashTable<T>::remove(const T& x)
{
typename std::list<T>::iterator iter; list<T> &whichlist = lists[myhash(x)];
iter = find(whichlist.begin(),whichlist.end(),x);
if( iter != whichlist.end())
{
whichlist.erase(iter);
currentSize--;
return 1;
}
return 0;
}
template <class T> int HashTable<T>::contains(const T& x)
{
list<T> whichlist;
typename std::list<T>::iterator iter;
whichlist = lists[myhash(x)];
iter = find(whichlist.begin(),whichlist.end(),x);
if ( iter != whichlist.end())
return 1;
return 0;
}
template <class T> void HashTable<T>::make_empty()
{
for(int i=0;i<lists.size();i++)
lists[i].clear();
currentSize = 0;
return 0;
}
template < class T > void HashTable < T >::rehash()
{
vector < list < T > >oldLists = lists;
lists.resize(nextPrime(2 * lists.size()));
for (int i = 0; i < lists.size(); i++)
lists[i].clear();
currentSize = 0;
for (int i = 0; i < oldLists.size(); i++) {
typename std::list < T >::iterator iter = oldLists[i].begin();
while (iter != oldLists[i].end())
insert(*iter++);
}
}
template < class T > void HashTable < T >::display() const const
{
for (int i = 0; i < lists.size(); i++) {
cout << i << ": ";
typename std::list < T >::const_iterator iter = lists[i].begin();
while (iter != lists[i].end()) {
cout << *iter << " ";
++iter;
}
cout << endl;
}
}
int nextPrime(const int n)
{
int ret, i;
ret = n;
while (1) {
int flag = 1;
for (i = 2; i < sqrt((float) ret); i++)
if (ret % i == 0) {
flag = 0;
break;
}
if (flag == 1)
break;
else {
ret = ret + 1;
continue;
}
}
return ret;
}
哈希表.cpp：
// HashTable.cpp :
// #include "stdafx.h"
#include "Hash.h"
int _tmain(int argc, _TCHAR * argv[])
{
Employee e1("Tom", 6000);
Employee e2("Anker", 7000);
Employee e3("Jermey", 8000);
Employee e4("Lucy", 7500);
HashTable < Employee > emp_table(13);
emp_table.insert(e1);
emp_table.insert(e2);
emp_table.insert(e3);
emp_table.insert(e4);
cout << "Hash table is: " << endl;
emp_table.display();
if (emp_table.contains(e4) == 1)
cout << "Tom is exist in hash table" << endl;
if (emp_table.remove(e1) == 1)
cout << "Removing Tom form the hash table successfully" << endl;
if (emp_table.contains(e1) == 1)
cout << "Tom is exist in hash table" << endl;
else
cout << "Tom is not exist in hash table" << endl;
return 0;
}