C語言實現通用數據結構之通用集合(HashSet)

Posted on 2021-11-26 by WalkonNet

這是在通用鏈表的基礎上實現的集合，關於鏈表的實現參見：C語言實現通用數據結構之通用鏈表

註意集合中隻存儲瞭指針，沒有儲存實際的數據。

對於新的數據類型來說，需要自定義HashCode函數和equal函數。

下面還給出瞭幾個常見的hashCode函數和equal函數。

（1）HashCode函數

頭文件

/*************************
*** File myHashCode.h
**************************/
#ifndef MYHASHCODE_H_INCLUDED
#define MYHASHCODE_H_INCLUDED
 
#include <string.h>
 
#define HASHCODE_MULT 31
 
//默認的hashCode
int myHashCodeDefault(void * a);
 
//int類型hashCode
int myHashCodeInt(void * a);
 
//char類型的hashCode
int myHashCodeChar(void * a);
 
//string類型的hashCode
int myHashCodeString(void * a);
 
#endif // MYHASHCODE_H_INCLUDED

源文件

/*************************
*** File myHashCode.c
**************************/
#include "myHashCode.h"
 
//默認的hashCode
int myHashCodeDefault(void * a)
{
    return (int) a;
}
 
//int類型hashCode
int myHashCodeInt(void * a)
{
    int * aa = (int *) a;
    return *aa;
}
 
//char類型的hashCode
int myHashCodeChar(void * a)
{
    char *aa = (char *) a;
    return *aa;
}
 
//string類型的hashCode
int myHashCodeString(void * a)
{
    int re = 0;
    char *aa = (char *) a;
    while (*aa)
    {
        re += HASHCODE_MULT * *aa;
        aa++;
    }
    return re;
}

（2）equal函數

頭文件

/*************************
*** File myEqual.h
**************************/
#ifndef MYEQUAL_H_INCLUDED
#define MYEQUAL_H_INCLUDED
 
//默認的相等的方法
int myEqualDefault(void * a, void *b);
 
//int類型相等的方法
int myEqualInt(void * a, void *b);
 
//char類型相等的方法
int myEqualChar(void * a, void *b);
 
//string類型相等的方法
int myEqualString(void * a, void *b);
 
#endif // MYEQUAL_H_INCLUDED

源文件

/*************************
*** File myEqual.c
**************************/
#include "myEqual.h"
#include <string.h>
 
//默認的相等的方法
int myEqualDefault(void * a, void *b)
{
    return a == b;
}
 
//int類型相等的方法
int myEqualInt(void * a, void *b)
{
    int *aa = (int*) a;
    int *bb = (int *) b;
    return *aa == *bb;
}
 
//char類型相等的方法
int myEqualChar(void * a, void *b)
{
    char *aa = (char *) a;
    char *bb = (char *) b;
    return *aa = *bb;
}
 
//string類型相等的方法
int myEqualString(void * a, void *b)
{
    char *aa = (char *) a;
    char *bb = (char *) b;
    return strcmp(aa, bb)==0;
}

（3）HashSet

頭文件

#ifndef MYHASHSET_H_INCLUDED
#define MYHASHSET_H_INCLUDED
 
# include "myHashMap.h"
 
typedef struct myHashSet
{
    int size; //大小
    int initialCapacity; //初始容量
    float loadFactor; //加載因子
    int (*hashCode)(void *data);
    int (*equal)(void *data1, void *data2);
    MyList ** dataList;
} MyHashSet;
 
typedef struct myHashSetIterator
{
    int index; //第幾個鏈表
    MyHashSet *set;
    MyNode *current;
    int count; //第幾個數據
} MyHashSetIterator;
 
//創建HashSet
MyHashSet *createMyHashSet(int (*hashCode)(void *data),int (*equal)(void *data1,void *data2));
 
//使用全部參數創建HashSet
MyHashSet *createMyHashSetForAll(int initialCapacity,float loadFactor,int (*hashCode)(void *data),int (*equal)(void *data1,void *data2));
 
//釋放HashSet
void freeMyHashSet(MyHashSet * set);
 
//是否包含某個data
int myHashSetContains(MyHashSet * const set, void * const data);
 
//增加一條數據,返回是否添加成功
int myHashSetAddData(MyHashSet * const set, void * const data);
 
//數據的容量
int myHashSetGetSize(const MyHashSet * const set);
 
//創建迭代器
MyHashSetIterator* createMyHashSetIterator(MyHashSet * const set);
 
//釋放迭代器
void freeMyHashSetIterator(MyHashSetIterator* iterator);
 
//迭代器是否有下一個
int myHashSetIteratorHasNext(MyHashSetIterator* iterator);
 
//遍歷下一個元素
void* myHashSetIteratorNext(MyHashSetIterator* iterator);
 
//刪除一條數據，返回是否刪除成功
int myHashSetRemoveData(MyHashSet * const set, void * const data);
 
//將第二個Set的全部對象加入到第一個，返回增加的個數
int myHashSetAddAllSet(MyHashSet * set,MyHashSet *other);
 
//復制HashSet
MyHashSet* myHashSetCopy(MyHashSet * set);
 
//遍歷
void myHashSetOutput(MyHashSet *set, void(*pt)(void*));
 
#endif // MYHASHSET_H_INCLUDED

源文件

# include "myHashSet.h"
#include <stdlib.h>
//創建HashSet
MyHashSet *createMyHashSet(int(*hashCode)(void *data), int(*equal)(void *data1, void *data2))
{
    MyHashSet *re = malloc(sizeof(MyHashSet));
    re->size = 0;
    re->loadFactor = DEFAULT_LOAD_FACTOR;
    re->initialCapacity = DEFAULT_INITIAL_CAPACITY;
    re->dataList = (MyList **) malloc(sizeof(MyList*) * re->initialCapacity);
    re->hashCode = hashCode;
    re->equal = equal;
    for (int i = 0; i < re->initialCapacity; i++)
    {
        re->dataList[i] = createMySearchList(equal);
    }
    return re;
}
 
//使用全部參數創建HashSet
MyHashSet *createMyHashSetForAll(int initialCapacity, float loadFactor, int(*hashCode)(void *data), int(*equal)(void *data1, void *data2))
{
    MyHashSet *re = createMyHashSet(hashCode, equal);
    re->initialCapacity = initialCapacity;
    re->loadFactor = loadFactor;
    return re;
}
 
//釋放HashSet
void freeMyHashSet(MyHashSet * set)
{
    for (int i = 0; i < set->initialCapacity; i++)
    {
        freeMyList(set->dataList[i]);
    }
    free(set->dataList);
    free(set);
}
 
//是否包含某個data
int myHashSetContains(MyHashSet * const set, void * const data)
{
    int hasCode = (*(set->hashCode))(data);
    hasCode %= set->initialCapacity;
    if (hasCode<0)
        hasCode+=set->initialCapacity;
    int re = myListFindDataIndex(set->dataList[hasCode], data);
    return re > -1;
}
 
void rebuildMyHashSet(MyHashSet * set)
{
    int newSize = set->initialCapacity * 2;
    MyList **newdataList = (MyList **) malloc(sizeof(MyList*) * newSize);
    for (int i = 0; i < newSize; i++)
    {
        newdataList[i] = createMyList();
    }
    MyHashSetIterator* it = createMyHashSetIterator(set);
    while (myHashSetIteratorHasNext(it))
    {
        void * data = myHashSetIteratorNext(it);
        int hasCode = (*(set->hashCode))(data);
        hasCode %= newSize;
        myListInsertDataAtLast(newdataList[hasCode], data);
    }
    freeMyHashSetIterator(it);
    for (int i = 0; i < set->initialCapacity; i++)
    {
        freeMyList(set->dataList[i]);
    }
    free(set->dataList);
    set->dataList = newdataList;
    set->initialCapacity = newSize;
}
 
//增加一條數據,返回是否添加成功
int myHashSetAddData(MyHashSet * const set, void * const data)
{
    int hasCode = (*(set->hashCode))(data);
    hasCode %= set->initialCapacity;
    if (hasCode<0)
        hasCode+=set->initialCapacity;
    int re = myListFindDataIndex(set->dataList[hasCode], data);
    if (re == -1)
    {
        myListInsertDataAtLast(set->dataList[hasCode], data);
        (set->size)++;
        if (set->size > set->initialCapacity * set->loadFactor)
        {
            rebuildMyHashSet(set);
        }
        return 1;
    }
    return 0;
}
 
//數據的容量
int myHashSetGetSize(const MyHashSet * const set)
{
    return set->size;
}
 
//創建迭代器
MyHashSetIterator* createMyHashSetIterator(MyHashSet * const set)
{
    MyHashSetIterator* re = (MyHashSetIterator*) malloc(
                                sizeof(MyHashSetIterator));
    re->count = 0;
    re->index = 0;
    re->set = set;
    re->current = set->dataList[0]->first;
    return re;
}
 
//釋放迭代器
void freeMyHashSetIterator(MyHashSetIterator* iterator)
{
    free(iterator);
}
 
//迭代器是否有下一個
int myHashSetIteratorHasNext(MyHashSetIterator* iterator)
{
    return iterator->count < iterator->set->size;
}
 
//遍歷下一個元素
void* myHashSetIteratorNext(MyHashSetIterator* iterator)
{
    (iterator->count)++;
    while (!(iterator->current))
    {
        (iterator->index)++;
        iterator->current = iterator->set->dataList[iterator->index]->first;
    }
    void * re = iterator->current->data;
    iterator->current = iterator->current->next;
    return re;
}
 
//刪除一條數據，返回是否刪除成功
int myHashSetRemoveData(MyHashSet * const set, void * const data)
{
    int hasCode = (*(set->hashCode))(data);
    hasCode %= set->initialCapacity;
    if (hasCode<0)
        hasCode+=set->initialCapacity;
    int re = myListRemoveDataObject(set->dataList[hasCode], data);
    if (re)
    {
        (set->size)--;
    }
    return re;
}
 
//將第二個Set的全部對象加入到第一個，返回增加的個數
int myHashSetAddAllSet(MyHashSet * set,MyHashSet *other)
{
    int ssize=set->size;
    MyHashSetIterator * it=createMyHashSetIterator(other);
    while (myHashSetIteratorHasNext(it))
    {
        myHashSetAddData(set,myHashSetIteratorNext(it));
    }
    freeMyHashSetIterator(it);
    int re=set->size-ssize;
    return re;
}
 
//復制HashSet
MyHashSet* myHashSetCopy(MyHashSet * set)
{
    MyHashSet* re=createMyHashSetForAll(set->initialCapacity,set->loadFactor,set->hashCode,set->equal);
    myHashSetAddAllSet(re,set);
    return re;
}
 
//遍歷
void myHashSetOutput(MyHashSet *set, void(*pt)(void*))
{
    MyHashSetIterator * it=createMyHashSetIterator(set);
    while (myHashSetIteratorHasNext(it))
    {
        pt(myHashSetIteratorNext(it));
    }
    freeMyHashSetIterator(it);
}

（4）測試文件

/*************************
*** File main.c
*** test for MyHashSet
**************************/
#include <stdio.h>
#include <stdlib.h>
#include "myEqual.h"
#include "myHashCode.h"
#include "myHashSet.h"
 
#define S 10
 
char* strs[S]=
{
    "abc",
    "qq",
    "hello",
    "abc",
    "lmy",
    "ab",
    "qq",
    "lqw",
    "sww",
    "lqw"
};
 
 
int main()
{
    //創建集合需要指定兩個函數，hashCode函數和equal函數。
    MyHashSet * set = createMyHashSet(myHashCodeString, myEqualString);
 
    //插入數據
    for (int i=0; i<S; i++)
    {
        myHashSetAddData(set, strs[i]);
    }
 
    //輸出大小
    printf("size=%d\n",myHashSetGetSize(set));
 
    //測試刪除
    myHashSetRemoveData(set,"qq");
    myHashSetRemoveData(set,"ab");
    myHashSetRemoveData(set,"qwert");
 
    //輸出大小
    printf("after remove size=%d\n",myHashSetGetSize(set));
 
    //遍歷
    MyHashSetIterator * it = createMyHashSetIterator(set);
    while(myHashSetIteratorHasNext(it))
    {
        char * pp= myHashSetIteratorNext(it);
        puts(pp);
    }
    //釋放遍歷器
    freeMyHashSetIterator(it);
 
    //釋放集合
    freeMyHashSet(set);
    return 0;
}

以上就是本文的全部內容，希望對大傢的學習有所幫助，也希望大傢多多支持WalkonNet。

C語言實現通用數據結構之通用集合(HashSet)

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