C语言实现常用数据结构
实现了链表，栈、哈希表等
哈希表由数组加链表实现。通过计算key的哈希值，将哈希值转成int类型并与数组长度进行与运算得到数组下标，数组每个元素都是一个链表，默认为NULL。
通过InitHashTable函数得到初始化的哈希表。已实现功能有：添加键值、删除键值、根据键获取值，清理所有键值对、回收哈希表，可以根据例子遍历键值。
Key可以扩展为任何类型，但需要实现相应类型HashCode的算法，此处只支持字符串类型。
md5.h
#pragma once
#ifndef MD5_H
#define MD5_H
typedef struct
{
unsigned int count[2];
unsigned int state[4];
unsigned char buffer[64];
}MD5_CTX;
#define F(x,y,z) ((x & y) | (~x & z))
#define G(x,y,z) ((x & z) | (y & ~z))
#define H(x,y,z) (x^y^z)
#define I(x,y,z) (y ^ (x | ~z))
#define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n)))
#define FF(a,b,c,d,x,s,ac) \
{ \
a += F(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
#define GG(a,b,c,d,x,s,ac) \
{ \
a += G(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
#define HH(a,b,c,d,x,s,ac) \
{ \
a += H(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
#define II(a,b,c,d,x,s,ac) \
{ \
a += I(b,c,d) + x + ac; \
a = ROTATE_LEFT(a,s); \
a += b; \
}
void MD5Init(MD5_CTX *context);
void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen);
void MD5Final(MD5_CTX *context, unsigned char digest[16]);
void MD5Transform(unsigned int state[4], unsigned char block[64]);
void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len);
void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len);
#endif
md5.c
#include <memory.h>
#include "md5.h"
unsigned char PADDING[] = { 0x80,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
void MD5Init(MD5_CTX *context)
{
context->count[0] = 0;
context->count[1] = 0;
context->state[0] = 0x67452301;
context->state[1] = 0xEFCDAB89;
context->state[2] = 0x98BADCFE;
context->state[3] = 0x10325476;
}
void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen)
{
unsigned int i = 0, index = 0, partlen = 0;
index = (context->count[0] >> 3) & 0x3F;
partlen = 64 - index;
context->count[0] += inputlen << 3;
if (context->count[0] < (inputlen << 3))
context->count[1]++;
context->count[1] += inputlen >> 29;
if (inputlen >= partlen)
{
memcpy(&context->buffer[index], input, partlen);
MD5Transform(context->state, context->buffer);
for (i = partlen; i + 64 <= inputlen; i += 64)
MD5Transform(context->state, &input[i]);
index = 0;
}
else
{
i = 0;
}
memcpy(&context->buffer[index], &input[i], inputlen - i);
}
void MD5Final(MD5_CTX *context, unsigned char digest[16])
{
unsigned int index = 0, padlen = 0;
unsigned char bits[8];
index = (context->count[0] >> 3) & 0x3F;
padlen = (index < 56) ? (56 - index) : (120 - index);
MD5Encode(bits, context->count, 8);
MD5Update(context, PADDING, padlen);
MD5Update(context, bits, 8);
MD5Encode(digest, context->state, 16);
}
void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len)
{
unsigned int i = 0, j = 0;
while (j < len)
{
output[j] = input[i] & 0xFF;
output[j + 1] = (input[i] >> 8) & 0xFF;
output[j + 2] = (input[i] >> 16) & 0xFF;
output[j + 3] = (input[i] >> 24) & 0xFF;
i++;
j += 4;
}
}
void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len)
{
unsigned int i = 0, j = 0;
while (j < len)
{
output[i] = (input[j]) |
(input[j + 1] << 8) |
(input[j + 2] << 16) |
(input[j + 3] << 24);
i++;
j += 4;
}
}
void MD5Transform(unsigned int state[4], unsigned char block[64])
{
unsigned int a = state[0];
unsigned int b = state[1];
unsigned int c = state[2];
unsigned int d = state[3];
unsigned int x[64];
MD5Decode(x, block, 64);
FF(a, b, c, d, x[0], 7, 0xd76aa478); /* 1 */
FF(d, a, b, c, x[1], 12, 0xe8c7b756); /* 2 */
FF(c, d, a, b, x[2], 17, 0x242070db); /* 3 */
FF(b, c, d, a, x[3], 22, 0xc1bdceee); /* 4 */
FF(a, b, c, d, x[4], 7, 0xf57c0faf); /* 5 */
FF(d, a, b, c, x[5], 12, 0x4787c62a); /* 6 */
FF(c, d, a, b, x[6], 17, 0xa8304613); /* 7 */
FF(b, c, d, a, x[7], 22, 0xfd469501); /* 8 */
FF(a, b, c, d, x[8], 7, 0x698098d8); /* 9 */
FF(d, a, b, c, x[9], 12, 0x8b44f7af); /* 10 */
FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */
/* Round 2 */
GG(a, b, c, d, x[1], 5, 0xf61e2562); /* 17 */
GG(d, a, b, c, x[6], 9, 0xc040b340); /* 18 */
GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
GG(b, c, d, a, x[0], 20, 0xe9b6c7aa); /* 20 */
GG(a, b, c, d, x[5], 5, 0xd62f105d); /* 21 */
GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
GG(b, c, d, a, x[4], 20, 0xe7d3fbc8); /* 24 */
GG(a, b, c, d, x[9], 5, 0x21e1cde6); /* 25 */
GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
GG(c, d, a, b, x[3], 14, 0xf4d50d87); /* 27 */
GG(b, c, d, a, x[8], 20, 0x455a14ed); /* 28 */
GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
GG(d, a, b, c, x[2], 9, 0xfcefa3f8); /* 30 */
GG(c, d, a, b, x[7], 14, 0x676f02d9); /* 31 */
GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */
/* Round 3 */
HH(a, b, c, d, x[5], 4, 0xfffa3942); /* 33 */
HH(d, a, b, c, x[8], 11, 0x8771f681); /* 34 */
HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
HH(a, b, c, d, x[1], 4, 0xa4beea44); /* 37 */
HH(d, a, b, c, x[4], 11, 0x4bdecfa9); /* 38 */
HH(c, d, a, b, x[7], 16, 0xf6bb4b60); /* 39 */
HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
HH(d, a, b, c, x[0], 11, 0xeaa127fa); /* 42 */
HH(c, d, a, b, x[3], 16, 0xd4ef3085); /* 43 */
HH(b, c, d, a, x[6], 23, 0x4881d05); /* 44 */
HH(a, b, c, d, x[9], 4, 0xd9d4d039); /* 45 */
HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
HH(b, c, d, a, x[2], 23, 0xc4ac5665); /* 48 */
/* Round 4 */
II(a, b, c, d, x[0], 6, 0xf4292244); /* 49 */
II(d, a, b, c, x[7], 10, 0x432aff97); /* 50 */
II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
II(b, c, d, a, x[5], 21, 0xfc93a039); /* 52 */
II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
II(d, a, b, c, x[3], 10, 0x8f0ccc92); /* 54 */
II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
II(b, c, d, a, x[1], 21, 0x85845dd1); /* 56 */
II(a, b, c, d, x[8], 6, 0x6fa87e4f); /* 57 */
II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
II(c, d, a, b, x[6], 15, 0xa3014314); /* 59 */
II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
II(a, b, c, d, x[4], 6, 0xf7537e82); /* 61 */
II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
II(c, d, a, b, x[2], 15, 0x2ad7d2bb); /* 63 */
II(b, c, d, a, x[9], 21, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
m_hashtable.h
#pragma once
#ifndef MaxHashTableLength
#include <stdio.h>
#define MaxHashTableLength 16
typedef char* Key;
typedef void* Value;
typedef unsigned char byte;
byte* int2byte(int32_t num);
typedef struct HashElem
{
Key key;
Value value;
struct HashElem* next;
int linkLen;
}hash_elem;
typedef struct HashTable
{
hash_elem* data[MaxHashTableLength];
int size;
}hash_table;
unsigned char* GetHashCode(unsigned char* msg);
int GetTableIndex(unsigned char* hash_code);
hash_table* InitHashTable();
void ClearHashTable(hash_table* table);
void DestroyHashTable(hash_table** table);
void RemoveElem(hash_table* table, Key key);
void UpdateValue(hash_table* table, Key key, Value newValue);
hash_elem* GetElem(hash_table* table, Key key);
Value GetValue(hash_table* table, Key key);
#endif
m_hashtable.c
#pragma once
#include "m_hashtable.h"
#include <stdint.h>
#include <stdlib.h>
#include "md5.h"
#include "Util.h";
unsigned char* GetHashCode(unsigned char* encrypt) //MD5加密
{
MD5_CTX md5;
uint8_t * decrypt = malloc(16);
MD5Init(&md5);
MD5Update(&md5, encrypt, strlen(encrypt));
MD5Final(&md5, decrypt);
//for (int i = 0; i < 16; i++) //测试打印
//{
// printf("%02x", decrypt[i]);
//}
//printf("\n");
return decrypt;
}
int GetTableIndex(unsigned char* hash_bytes) //将MD5码转成int，并限制在MaxHashTableLength - 1内
{
int hash_code = byte2int(hash_bytes); //MD5码转int
//sscanf_s(hash_bytes, "%d",hash_code);
return hash_code & (MaxHashTableLength - 1);
}
hash_table * InitHashTable()
{
hash_table* table = (hash_table*)malloc(sizeof(hash_table));
table->size = 0;
for (int i = 0; i < MaxHashTableLength; i++)
{
table->data[i] = NULL; //初始化地址
}
return table;
}
void ClearHashTable(hash_table* table)
{
for (int i = 0; i < MaxHashTableLength; i++)
{
hash_elem* temp = table->data[i];
if (temp == NULL)
{
continue;
}
int linkLen = temp->linkLen;
for (int j = 1; j < linkLen; j++) //回收首节点后续节点
{
hash_elem* node = temp;
hash_elem* pre = node;
for (int k = 1; k < temp->linkLen; k++) //找到倒数第一个节点
{
pre = &(*node);
node = node->next;
}
free(node); //回收最后一个节点内存
pre->next = NULL;
temp->linkLen--; //该条链表长度减一
}
free(temp); //回收该条链表首节点
table->data[i] = NULL;
}
}
void DestroyHashTable(hash_table** table)
{
ClearHashTable(*table);
free(*table);
*table = NULL;
}
void AddElem(hash_table* table, hash_elem * elem)
{
uint8_t* hash_code = GetHashCode(elem->key); //计算key的哈希值
int index = GetTableIndex(hash_code);
if (table->data[index] == NULL) //该节点未有数据，占用首节点
{
table->data[index] = elem;
elem->next = NULL;
elem->linkLen = 1;
}
else
{
hash_elem* origin = table->data[index];
if (m_str_cmp(origin->key, elem->key) == 0)//首节点比较key是否已存在
{
printf("key已存在，key=%s", elem->key);
return;
}
for (int i = 1; i < origin->linkLen; i++) //找到该链表最后一个节点
{
if (m_str_cmp(origin->key, elem->key) == 0)
{
printf("key已存在，key=%s", elem->key);
return;
}
origin = origin->next;
}
origin->next = elem;
elem->next = NULL;
table->data[index]->linkLen++;
}
table->size++;
}
void RemoveElem(hash_table * table, Key key)
{
uint8_t* hash_code = GetHashCode(key);
int index = GetTableIndex(hash_code);
if (table->data[index] == NULL)
{
printf("remove elem error,index=%d is null", index);
return;
}
hash_elem* current = table->data[index];
hash_elem* pre = current;
for (int i = 1; i <= table->data[index]->linkLen; i++)
{
if (m_str_cmp(current->key, key) == 0) //找到键了
{
if (current == pre)
{
table->data[index] = current->next; //首节点移除
int linkLen = current->linkLen; //获取这条链表长度
if (linkLen > 1)
{
table->data[index]->linkLen = linkLen - 1; //链表长度减1
}
else
{
table->data[index] = NULL;
}
free(current);
current = NULL;
}
else if (current->next != NULL) //中间节点移除，连接断续节点
{
pre->next = &(*current->next);
free(current);
current = NULL;
table->data[index]->linkLen--;
}
else
{
pre->next = NULL; //尾节点移除
free(current);
current = NULL;
table->data[index]->linkLen--;
}
table->size--;
return;
}
pre = &(*current);
current = current->next;
}
}
void UpdateValue(hash_table * table, Key key, Value newValue)
{
hash_elem* elem = GetElem(table, key);
if (elem==NULL)
{
printf("update value faild,key=%s is null", key);
return;
}
else
{
elem->value = newValue;
}
}
hash_elem * GetElem(hash_table * table, Key key)
{
uint8_t* hash_code = GetHashCode(key);
int index = GetTableIndex(hash_code);
if (table->data[index] == NULL)
{
printf("get value,index=%d is null", index);
return NULL;
}
hash_elem* current = table->data[index];
for (int i = 1; i <= table->data[index]->linkLen; i++)
{
if (m_str_cmp(current->key, key) == 0)
{
return current;
}
current = current->next;
}
printf("key not find,key=%s", key);
}
Value GetValue(hash_table* table, Key key)
{
hash_elem* elem = GetElem(table, key);
if (elem==NULL)
{
return NULL;
}
else
{
return elem->value;
}
}
int32_t byte2int(byte* bytes)
{
return (int)((((bytes[3] & 0xff) << 24)
| ((bytes[2] & 0xff) << 16)
| ((bytes[1] & 0xff) << 8) | ((bytes[0] & 0xff) << 0)));
}
测试使用
int main()
{
hash_table* table=InitHashTable();
hash_elem* elem = (hash_elem*)malloc(sizeof(hash_elem));
elem->key = "1";
elem->value = "my1";
AddElem(table, elem);
hash_elem* elem2= (hash_elem*)malloc(sizeof(hash_elem));
elem2->key = "2";
elem2->value = "my2";
AddElem(table, elem2);
hash_elem* elem3 = (hash_elem*)malloc(sizeof(hash_elem));
elem3->key = "3";
elem3->value = "my3";
AddElem(table, elem3);
//hash_elem* elem4 = (hash_elem*)malloc(sizeof(hash_elem));
//elem4->key = "asd";
//elem4->value = "my5";
//AddElem(table, elem4);
//RemoveElem(table,“1”);
//RemoveElem(table, "2");
RemoveElem(table, "3");
UpdateValue(table, "1", "hello");
//ClearHashTable(table);
//DestroyHashTable(&table);
if (table==NULL)
{
return;
}
for (int i = 0; i < MaxHashTableLength; i++)
{
hash_elem* temp = table->data[i];
if (temp==NULL)
{
continue;;
}
for (int j = 0; j < table->data[i]->linkLen; j++)
{
printf("\nkey=%s,value=%s",temp->key,temp->value);
temp = temp->next;
}
}
return 0;
}
