ADT—散列表

 

#ifndef _MAP_H_
#define _MAP_H_

#include <iostream>
struct nlist
{
    nlist *next;
    int keys;
    int value;
};

class Map
{
public:
    Map();
    ~Map();

    
    int GetLength();
    nlist * Insert ( int key,int newValue );
    void Delete (int serchKey);
    void Retrieve (int serchKey);
    nlist * hashtable_search(int key);

    void printfMap();

    nlist *hashtable[101];
protected:
    int hashFun ( int key)
    {
        key*=key;
        key/=100; //先求平方值，后去掉末尾的两位数
        return key%1000; //取中间三位数作为散列地址返回        
    };
};

#endif

 

#include "map.h"

using std::cout;
using std::endl;

Map::Map ()
{
    for (int i = 0;i <= 100;i++)
        hashtable[i] = NULL;
}

Map::~Map()
{    
    for(int i=0;i<101;i++)
    {
            delete hashtable[i];
    }
}

nlist * Map::Insert (int key,int newValue)
{
    nlist *np = new nlist;
    int hashval = 0;
    
    hashval = hashFun (key);
    np->value = newValue;
    np->keys = key;
    np->next = hashtable[hashval];
    hashtable[hashval] = np;
    return np;
 }

nlist * Map::hashtable_search(int key)
{
    nlist *np = new nlist;

    while(np != NULL)
    {
        if (key == np->keys)  
            return np;
        else 
            return NULL;
    }
}

void Map::printfMap ()
{
    nlist *np = new nlist;

    for (int i =0;i<101;i++)
    {
        np = hashtable[i];
        while (np )
        {
            std::cout<<np->keys<<"\t"<<np->value<<endl;
            np = np->next;
        }
    }
}

int main()
{
    Map m;

    m.Insert (7,343);
    m.Insert (3,56);
    m.Insert (2,6);
    m.Insert (4,65);

    m.printfMap();

    return 0;
}