哈希表类

C++ code

#include "stdafx.h"
#pragma once
#define IDType int

//哈希函数：除留余数法。冲突处理：链地址法
template <class T>
class CDict
{
public:
    CDict(int storeL)
    {
        if(storeL>0)
            storeLen=storeL;
        else
            storeLen=100;
        initProc();
    }
    CDict()
    {
        storeLen=100;
        initProc();
    }
    //增加
    bool Add(IDType ID,T data)
    {
        if(Find(ID))//保持主键唯一
            return 0;
        else{
        //新建节点
        HNode * tmp=new HNode;
        tmp->next=NULL;
        tmp->ID=ID;
        tmp->data=data;
        //获得链地址
        int pos=ID % storeLen;
        //检测冲突
        if(!ChainHash[pos]) 
            ChainHash[pos]=tmp;
        else{
            HNode * rear=ChainHash[pos];
            while(rear->next) rear=rear->next;
            rear->next=tmp;
        }
        return 1;
        }
    }
    //删除
    bool Delete(IDType ID)
    {
        //获得链地址
        int pos=ID % storeLen;
        //检测冲突
        if(ChainHash[pos]) 
        {
            HNode * rear=ChainHash[pos];
            if(rear->ID==ID)//在首地址就找到了数据
            {
                ChainHash[pos]=rear->next;
                delete rear;
            }
            else{
                while(rear->next)
                {
                    if(rear->next->ID==ID)
                    {
                        //勾连
                        HNode * tmp=rear->next;
                        rear->next=tmp->next;
                        delete tmp;
                        return 1;
                    }
                    rear=rear->next;
                }
            }
        }
        return 0;
    }
    bool SetAt(IDType ID,T data)
    {
        int pos=ID % storeLen;
        //检测冲突
        if(ChainHash[pos]) 
        {
            HNode * rear=ChainHash[pos];
            while(rear)
            {
                if(rear->ID==ID) 
                {
                    rear->data=data;
                    return 1;
                }
                rear=rear->next;
            }
        }
        return 0;
    }
    T Find(int ID)
    {
        int pos=ID % storeLen;
        //检测冲突
        if(ChainHash[pos]) 
        {
            HNode * rear=ChainHash[pos];
            while(rear)
            {
                if(rear->ID==ID) return rear->data;
                rear=rear->next;
            }
        }
        return NULL;
    }
    void showStruct()
    {
        int i=0;
        for(i=0;i<storeLen;i++)
        {
            if(ChainHash[i]) 
            {
                HNode * rear=ChainHash[i];
                while(rear)
                {
                    printf(" → (%d,%d)",rear->ID,rear->data);
                    rear=rear->next;
                }
                printf(" → ∧");
            }
            else printf("∧");
            printf("
");
        }
    }
protected:
private:
    int storeLen;
    //构造数据结构：存放冲突数据的链表
    typedef struct HNode{
        T data;//数据域
        struct HNode* next;//指针域
        IDType ID;//主键域
    }HNode;
    //构造链哈希表用于存放HNode的地址
    HNode** ChainHash;
    void initProc()
    {
        //构造链哈希表
        ChainHash=new HNode*[storeLen];//ChainHash[ num ]的数据类型是HNode*，用来指向存储节点。
        int i;
        for(i=0;i<storeLen;i++) ChainHash[i]=NULL;//初始化
    }
};