C++ 哈希表 (hashtable) 用于保存简单的数据，及数据查找，数据删除

/*hashtable.h*/

#include<iostream>
#include <string>
#include<vector>
using namespace std;

class Hashtable
{
protected:
	typedef pair<int,string> TIntStrPair;

	typedef pair<int, TIntStrPair> TIIntStrPair;
	typedef pair<string,string> TStrStrPair;
	typedef pair<string, TStrStrPair> TSStrStrPair;
private:
    vector <TSStrStrPair> Table; // <string, <string, string>> ; 

public:

    int hashfunc(string s);
    string HashFunc(string value); //generate 20 位随机数
    void add_hash_(string key, string);
    string search_(string value);
    void list_hash();
    void print_hash(string hashIndex);
    bool delete_hash(string value); 

};

　　

/*hashtable.cpp*/

#include "hashtable.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

using namespace std;

int Hashtable::hashfunc(string s) {

	int i, sum=0;
	for(i=0; i < (int)s.size(); i++)
		sum=sum+s[i];
	int result;
	result = (sum-1)%20;
}

string Hashtable::HashFunc(string value) {
	string x;

           char CCH[] = "_0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_";
	char str[6];
	char ss[21];
	int i=0;
	static int count = 0;
	count++;
	//srand((char)(time((time_t *)NULL)));
	srand((char)(sizeof(value.c_str()) + count ));
	//srand((char)(sizeof(value.c_str())));
	for (i = 0; i < 15; i++) {
		ss[i] = (char)(rand()%27 + 'a');
	}
	ss[i] = '\0';

	srand((char)(time((time_t *)NULL)));
	//srand((char)(sizeof(CCH)));
	for (i = 0; i < 5; i++) {
	int y = rand() / (RAND_MAX/(sizeof(CCH) - 1 + count ));
		str[i] = CCH[y];
	}
	str[i] = '\0';
	//printf("str = %s\n", str);

	strcat(ss,str);

	x = ss;
	return x;
}

void Hashtable::add_hash_(string key, string s) {
	std::pair<string,TStrStrPair> Temp;
 	string hashIndex_;
	hashIndex_ = HashFunc(s);		

	Temp.first = hashIndex_;
	Temp.second.first = key;
	Temp.second.second = s;

	Table.push_back(Temp);

}

string Hashtable::search_(string value) {

	string hashIndex;
	for (int x = 0; x < Table.size(); x++) {
		if (Table.at(x).second.second == value) {
				hashIndex = Table.at(x).first;
				cout << "Match " << value << " in the list" << endl;
				return hashIndex;
		}

		if (x == Table.size()) {
			cout << "Not match " << value << " in the list " << endl;
			//return hashIndex;
		}
		}

			return hashIndex;

}

void Hashtable::print_hash(string hashIndex) {
	if (hashIndex.size() == 0) {
		cout << "Not found in the list " << endl;
		return;
	}
	cout << "Hash Num: " << hashIndex << endl;
	for (int i = 0; i < Table.size(); i++) {
		if (Table.at(i).first == hashIndex) {
			cout << "Key = " << Table.at(i).second.first << endl;
			cout << "Value = " << Table.at(i).second.second << endl;
		}
	}
}

bool Hashtable::delete_hash(string value) {

	for (int x = 0; x < Table.size(); x++) {
		if (Table.at(x).second.second == value) {
				Table.erase(Table.begin() + x);
				return true;
		}
	}

	return false;

}

void Hashtable::list_hash() {

	if (Table.empty()) {
		cout << "There is not element in the list" << endl;
		return;
	}

	for (int x = 0; x < Table.size(); x++) {
		cout << "Hash Num: " << Table.at(x).first << endl;;
		cout << "Key: " << Table.at(x).second.first << endl;
		cout << "Value: " << Table.at(x).second.second << endl;
		cout << endl;
	}

}

　　

/*main.cpp*/

#include"hashtable.h"
#include<iostream>

int  main()
{
    string hashIndex;
    Hashtable ht;
    ht.add_hash_("", "Tom");
    //sleep(1);
    ht.add_hash_("", "Mary");
    //sleep(1);
    ht.add_hash_("", "jimes");
    ht.add_hash_("", "fantex");
    ht.add_hash_("", "beyond");

    ht.list_hash();

     hashIndex = ht.search_("Mary");
     ht.print_hash(hashIndex);

     cout << "delete element " << endl;
     ht.delete_hash("jimes");
     ht.list_hash();

    //ht.search_("Mary");

    return ;
}

运行结果：

$ g++ -o new-t main.cpp hashtable.cpp

Administrator@WIN7-20131114US /cygdrive/i/HashTable
$ ./new-t
Hash Num: ovbcmuxpydnpasuK2ibP
Key: 1
Value: Tom

Hash Num: xtsoaxrledvaxswL2jbQ
Key: 2
Value: Mary

Hash Num: rruaq{bwbnnxdtjM2jbR
Key: 3
Value: jimes

Hash Num: {pwmecmrznft{imN2jbR
Key: 4
Value: fantex

Hash Num: inyzdfwmvxyfgjpN2kbS
Key: 5
Value: beyond

Match Mary in the list
Hash Num: xtsoaxrledvaxswL2jbQ
Key = 2
Value = Mary
delete element
Hash Num: ovbcmuxpydnpasuK2ibP
Key: 1
Value: Tom

Hash Num: xtsoaxrledvaxswL2jbQ
Key: 2
Value: Mary

Hash Num: {pwmecmrznft{imN2jbR
Key: 4
Value: fantex

Hash Num: inyzdfwmvxyfgjpN2kbS
Key: 5
Value: beyond

　　

参考文章：http://blog.csdn.net/jjiang06/article/details/6706134