C里面怎样定义hash表啊？

[kiono]

我现在要定义一个User的hash表，把它放到hash表里面，userid作为Key，Vlue是userName，userPhone，userCert的集合或者struct，看怎样实现方便，C我不熟悉，所以请教一下大家。请大家教我一下，完整的构建这个hashTable的完整代码，谢谢了。

[kiono]

是在C里面，不是C＋＋

[yyyapple]

.h

/*
 * Copyright (c) 1990, 1991 Stanford University
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Stanford not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  Stanford makes no representations about
 * the suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * STANFORD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
 * IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * UHash - hash table.
 */

#ifndef unidraw_uhash_h
#define unidraw_uhash_h

#include <InterViews/defs.h>

class Iterator;
class UList;

class UHashElem {
public:
    UHashElem(void* = nil);
    virtual ~UHashElem();

    void* GetKey();
    void SetKey(void*);
private:
    void* _key;
};

inline void* UHashElem::GetKey () { return _key; }
inline void UHashElem::SetKey (void* key) { _key = key; }

class UHashTable {
public:
    UHashTable(int nslots);
    virtual ~UHashTable();

    virtual void Register(void* key, UHashElem* = nil);
    virtual void Unregister(void* key);

    void First(Iterator&);
    void Next(Iterator&);
    boolean Done(Iterator);

    UHashElem* GetElem(Iterator);
    UHashElem* Find(void* key);
protected:
    virtual UHashElem* CreateElem();
    virtual int Hash(void*);
protected:
    int _nslots;
private:
    UList* UElem(Iterator);
    UHashElem* Elem(UList*);
    void DeleteSlot(UList*);
private:
    UList** _slot;
};

#endif

.c

/*
 * Copyright (c) 1990, 1991 Stanford University
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Stanford not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  Stanford makes no representations about
 * the suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * STANFORD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
 * IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * UHash implementation.
 */

#include <Unidraw/iterator.h>
#include <Unidraw/uhash.h>
#include <Unidraw/ulist.h>

#include <OS/memory.h>

/*****************************************************************************/

UHashElem::UHashElem (void* key) { _key = key; }
UHashElem::~UHashElem () { }

/*****************************************************************************/

UHashElem* UHashTable::CreateElem () { return nil; }
UHashElem* UHashTable::Elem (UList* r) { return (UHashElem*) (*r)(); }
int UHashTable::Hash (void* c) { return (unsigned) c % _nslots; }

UHashTable::UHashTable (int nslots) {
    _nslots = nslots;
    _slot = new UList*[_nslots];
    Memory::zero(_slot, sizeof(void*) * _nslots);
}

UHashTable::~UHashTable () {
    for (int i = 0; i < _nslots; ++i) {
        if (_slot[i] != nil) {
            DeleteSlot(_slot[i]);
        }
    }
    delete _slot;
}

void UHashTable::Register (void* key, UHashElem* elem) {
    int n = Hash(key);

    if (_slot[n] == nil) 
	{
        _slot[n] = new UList;
    }
    if (elem == nil) {
        elem = CreateElem();
    }
    elem->SetKey(key);
    _slot[n]->Prepend(new UList(elem));
}

void UHashTable::Unregister (void* key) {
    int n = Hash(key);
    UList* slot = _slot[n];

    if (slot != nil) {
        for (UList* u = slot->First(); u != slot->End(); u = u->Next()) {
            UHashElem* elem = Elem(u);

            if (elem->GetKey() == key) {
                slot->Remove(u);
                delete elem;
                delete u;
                break;
            }
        }
    }
}

UList* UHashTable::UElem (Iterator i) { return (UList*) i.GetValue(); }
UHashElem* UHashTable::GetElem (Iterator i) { return Elem(UElem(i)); }

void UHashTable::First (Iterator& i) {
    for (int j = 0; j < _nslots; ++j) {
        if (_slot[j] != nil) {
            i.SetValue(_slot[j]->First());
            return;
        }
    }
    i.SetValue(nil);
}

void UHashTable::Next (Iterator& i) {
    UHashElem* elem = GetElem(i);

    if (elem != nil) {
        int n = Hash(elem->GetKey());
        UList* u = UElem(i);
        u = u->Next();

        if (u == _slot[n]->End()) {
            for (int j = n+1; j < _nslots; ++j) {
                if (_slot[j] != nil) {
                    u = _slot[j]->First();
                    break;
                }
            }
        }
        i.SetValue(u);
    }
}

boolean UHashTable::Done (Iterator i) {
    for (int j = _nslots - 1; j >= 0; --j) {
        if (_slot[j] != nil) {
            return UElem(i) == _slot[j]->End();
        }
    }
    return true;
}

UHashElem* UHashTable::Find (void* key) {
    int n = Hash(key);
    UList* slot = _slot[n];

    if (slot != nil) {
        for (UList* u = slot->First(); u != slot->End(); u = u->Next()) {
            UHashElem* elem = Elem(u);

            if (elem->GetKey() == key) {
                return elem;
            }
        }
    }
    return nil;
}

void UHashTable::DeleteSlot (UList* slot) {
    while (!slot->IsEmpty()) {
        UList* u = slot->First();
        slot->Remove(u);
        UHashElem* elem = Elem(u);
        delete elem;
        delete u;
    }
    delete slot;
}

[青葱岁月不可追]

up！~完整代码？？？？？期待ing

[ack2me]

自己写，标准c没有提供类似c++的算法库，考验你数据结构基本功的时候到了。

[kiono]

yyyapple 兄，谢谢了，好人啊！！！

[realdragon2]

HTtable * 是二级指针吧?

[kiono]

yyyapple写的是C＋＋的吧？因为C我一点都不熟悉，但是需要在Linux环境下编程，没办法，只能用C，怎样在C里定义一个HASHTABLE啊？？

[shailen126]

#include "stdafx.h"
#include <stdio.h>
#include <string.h>

typedef struct STUDENT //单元数组
{
char* name;
int score;
struct STUDENT* pnext;
}STUDENT;
STUDENT* Hashtab[100]; //HASH数组
void install(STUDENT* STR);
void CreateHashTab();
int HashNum(char* p);
void CreateHashTab() //每个单元赋值并插入HASH表
{
for (int i=0;i<100;i++)
{
STUDENT* str = new STUDENT;
str->name = new char(10);
sprintf(str->name,"Tom%d",i);
str->score = i;
str->pnext = NULL;
install(str);//插入HASH表
}

}
void install(STUDENT* STR)//插入HASH表
{
int h = HashNum(STR->name);
STR->pnext = Hashtab[h];
Hashtab[h] = STR;
}
int HashNum(char* p)//根据字符串计算HASH值
{
for (int i=0;*p;p++)
{
i = *p+31*i;
}
return i%100;
}

int main(int argc, char* argv[])
{
CreateHashTab();
printf("Hello World!\n");
return 0;
}

[太乙]

嗯，自己定义，用着方便！

[yyyapple]

[Quote=引用 5 楼 kiono 的回复:]
yyyapple写的是C＋＋的吧？因为C我一点都不熟悉，但是需要在Linux环境下编程，没办法，只能用C，怎样在C里定义一个HASHTABLE啊？？
[/Quote]

给你个c的，自己再补充点吧
.h

/* HASH.H
**
** Header file for Hash Table module HASH.C
**
*/

#define HTMAXSIZE 1999
#define NOTFOUND  0

struct HTentry
{
	char 	*key;
	int 	data;
	struct	HTentry *next;
};

typedef struct HTentry *HTtable;

HTtable *HTcreate(void);
int	HTinsert(HTtable *, char *, int);
int 	HTfind(HTtable *, char *);
void	HTfree(HTtable *);

.c

/* HASH.C
**
** Implementation of a simple Hash Table for string storage & retrieval
**
** Written by L. Rossman
**
** The hash table data structure (HTable) is defined in "hash.h".
** Interface Functions:
**    HTcreate() - creates a hash table
**    HTinsert() - inserts a string & its index value into a hash table
**    HTfind()   - retrieves the index value of a string from a table
**    HTfree()   - frees a hash table
**
*/

#include <malloc.h>
#include <string.h>
#include "hash.h"

int hash(char *key)
{
	int n = 0;
	char *ch = key;
	while (*ch)
	{
		n <<= 1;
		n += (*ch);
		++ch;
	}
	return(n % HTMAXSIZE);
}

HTtable *HTcreate()
{
	int i;
	HTtable *ht =
		(HTtable *) calloc(HTMAXSIZE, sizeof(HTtable));
	if (ht != NULL)
		for (i=0; i<HTMAXSIZE; i++) ht[i] = NULL;
	return(ht);
}
 
int	HTinsert(HTtable *ht, char *key, int data)
{
	int i = hash(key);
	struct HTentry *entry;
	if ((i < 0) || (i >= HTMAXSIZE)) return(0);
	entry = (struct HTentry *) malloc(sizeof(struct HTentry));
	if (entry == NULL) return(0);
	entry->key = key;
	entry->data = data;
	entry->next = ht[i];
	ht[i] = entry;
	return(1);
}
	
int 	HTfind(HTtable *ht, char *key)
{
	int i = hash(key);
	struct 	HTentry	*entry;
	if ((i < 0) || (i >= HTMAXSIZE)) return(NOTFOUND);
	entry = ht[i];
	while (entry != NULL)
	{
		if (strcmp(entry->key,key) == 0) return(entry->data);
		entry = entry->next;
	}
	return(NOTFOUND);
}

void	HTfree(HTtable *ht)
{
	struct 	HTentry	*entry,
			*nextentry;
	int i;
	for (i=0; i<HTMAXSIZE; i++)
	{
		entry = ht[i];
		while (entry != NULL)
		{
			nextentry = entry->next;
			free(entry);
			entry = nextentry;
		}
	}
	free(ht);
}

[kiono]

yyyapple,你发的看的不是很懂，能配上注释吗？像shailen126 那样。
能不能用我的User信息来举例啊？谢谢了～～～

[yyyapple]

[Quote=引用 9 楼 kiono 的回复:]
yyyapple,你发的看的不是很懂，能配上注释吗？像shailen126 那样。
能不能用我的User信息来举例啊？谢谢了～～～
[/Quote]

晕，建议你还是去看看什么叫hash table，不懂c怎么用啊

[kiono]

yyyapple 我也没办法啊，工作需要，我也痛苦，简单帮我注释一下吧。

[9527他大爷]

学习

[yyyapple]

抽点空，改了一下, 在vs2005下编译的
.h

/* HASH.H
**
** Header file for Hash Table module HASH.C
**
*/
#ifndef __HASH_H
#define __HASH_H

#define HTMAXSIZE 1999
#define NOTFOUND  0
#define MAXLEN    127
#ifdef __cplusplus
extern "C" {
#endif

struct HTdata  //用户数据
{
	char 	*key;
	char    *userName;
	char    *userPhone;
	char    *userCert;
}; 

typedef struct HTdata  *HTelem;

struct HTentry //hash table 结构 
{
	HTelem elem;
	struct	HTentry *next;
};


typedef struct HTentry *HTtable;

HTtable *HTcreate(void);  //创建hash table
int	HTinsert(HTtable *, char*, HTelem ); //根据用户提供的关键字和数据插入表格中
HTelem HTfind(HTtable *, char * ); //根据关键字，查找数据
void	HTfree(HTtable *); //释放hash table

	
#ifdef __cplusplus
}
#endif

#endif

.c

/* HASH.C
**
** Implementation of a simple Hash Table for string storage & retrieval
**
** Written by L. Rossman
**
** The hash table data structure (HTable) is defined in "hash.h".
** Interface Functions:
**    HTcreate() - creates a hash table
**    HTinsert() - inserts a string & its index value into a hash table
**    HTfind()   - retrieves the index value of a string from a table
**    HTfree()   - frees a hash table
**
*/

#include <malloc.h>
#include <string.h>
#include "hash.h"

int hash(char *key) //hash索引值算法
{
	int n = 0;
	char *ch = key;
	while (*ch)
	{
		n <<= 1;
		n += (*ch);
		++ch;
	}
	return(n % HTMAXSIZE);
}

HTtable *HTcreate() //创建hash table
{
	int i;
	HTtable *ht =
		(HTtable *) calloc(HTMAXSIZE, sizeof(HTtable));
	if (ht != NULL)
		for (i=0; i<HTMAXSIZE; i++) ht[i] = NULL;
	return(ht);
}
 
int	HTinsert(HTtable *ht, char* key, HTelem elem) //数据插入hash table，成功返回1，失败返回0
{
	int i = hash(key);
	struct HTentry *entry;
	if ((i < 0) || (i >= HTMAXSIZE) || (0==elem) ) return(0);
	entry = (struct HTentry *) malloc(sizeof(struct HTentry));
	if (entry == NULL) return(0);
	elem->key = key;
	entry->elem = elem;
	entry->next = ht[i];
	ht[i] = entry;
	return(1);
}
	
HTelem 	HTfind(HTtable *ht, char* key) //根据关键字查找用户数据，找到返回用户数据指针，否则返回空
{
	int i = hash(key);
	struct 	HTentry	*entry;
	if ((i < 0) || (i >= HTMAXSIZE)) return(NOTFOUND);
	entry = ht[i];
	while (entry != NULL)
	{
		if (strcmp(entry->elem->key, key) == 0) return(entry->elem);
		entry = entry->next;
	}
	return(NOTFOUND);
}

void	HTfree(HTtable *ht) //清空hash table
{
	struct 	HTentry	*entry,
			*nextentry;
	int i;
	for (i=0; i<HTMAXSIZE; i++)
	{
		entry = ht[i];
		while (entry != NULL)
		{
			nextentry = entry->next;
			free(entry);
			entry = nextentry;
		}
	}
	free(ht);
}

.c 测试主程序

#include "stdio.h"
#include "hash.h"

int main() 
{ 
	struct HTdata data[] = {
		{"1", "yyyapple", "777777", "1234567"},
		{"2", "yyyapple2", "777777", "1234567"},
		{"3", "yyyapple3", "777777", "1234567"}
	};
	HTtable* pt = HTcreate();

	for(int i=0;i <3; i++)
	{
	HTinsert(pt, data[i].key, &data[i]);
	}

	HTelem p1 = HTfind(pt, "2");

	printf("key = %s, userName = %s, userPhone = %s, userCert = %s\n",
		p1->key, p1->userName, p1->userPhone, p1->userCert);

	HTfree(pt);
	return 0; 
}

[wjlsmail]

Mark