hash表C语言实现

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <strings.h>
/*通过链接法解决碰撞*/
typedef const char* hash_key_type;
typedef int hash_value_type;
typedef int (*hash_fun)(hash_key_type key);
typedef bool (*equal_fun)(hash_key_type keya, hash_key_type keyb);

typedef struct list_node_tag {
hash_key_type key;
hash_value_type value;
struct list_node_tag *next;
} list_node;

typedef struct hash_tag {
list_node **list_array;
int num;
hash_fun f;
equal_fun e;
} hash;

hash *hash_create(int num, hash_fun f, equal_fun e){
hash *h = (hash*)malloc(sizeof(hash));
h->num = num;
h->f = f;
h->e = e;
h->list_array = (list_node**)calloc(sizeof(list_node*), num);
for (int i = 0; i < num; i++) {
h->list_array[i] = NULL;
}
return h;
}

void hash_destroy(hash *h){
for (int i = 0; i < h->num; i++) {
for(list_node * p = h->list_array[i]; p != NULL; ){
list_node * q = p;
p = p -> next;
free(q);
}
};
free(h->list_array);
free(h);
}

void hash_insert(hash *h, hash_key_type key, hash_value_type value){
list_node *x = (list_node*)malloc(sizeof(list_node));
x->key = key;
x->value = value;
int hval = h->f(key) % h->num;
x->next = h->list_array[hval];
h->list_array[hval] = x;
}

bool hash_search(hash *h, hash_key_type key, hash_value_type *value){
int hval = h->f(key) % h->num;
list_node *x = h->list_array[hval];
while (x != NULL && !h->e(x->key, key)) {
x = x->next;
}
if(x != NULL){
*value = x->value;
return true;
} else {
return false;
}
}

void hash_delete(hash *h, hash_key_type key){
int hval = h->f(key) % h->num;
list_node **head = &h->list_array[hval];
list_node *x = *head;
list_node *prev = NULL;
while(x != NULL && !h->e(x->key , key)){
prev = x;
x = x->next;
}
if(h->e(x->key, key)){
if(prev == NULL){
h->list_array[hval] = x->next;
} else {
prev->next = x->next;
}
free(x);
}
}

int hash_key_fun(hash_key_type key){
const char *str = (const char*)key;
int seed = 131;
int hash = 0;
while (*str){
hash = hash * seed + (*str++);
}
return (hash & 0x7FFFFFFF);
}

typedef struct node_tag{
char *str;
struct node_tag *next;
} node;

bool str_equal(const char *a, const char *b){
return strcmp(a, b) == 0;
}

int main(){
hash *h = hash_create(10, hash_key_fun, str_equal);
const char *str[10] = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"};
for (int i = 0; i < 10; i++) {
printf("key:%s,value:%d\n", str[i], i);
hash_insert(h, str[i], i);
}
printf("\n");
for (int i = 0; i < 10; i++) {
int value;
bool result = hash_search(h, str[i], &value);
printf("查找关键字:%s的结果:%s,value:%d\n", str[i], result ? "true" : "false", value);
hash_delete(h, str[i]);
result = hash_search(h, str[i], &value);
printf("删除关键字:%s的结果:%s\n", str[i], result ? "false" : "true");
}
hash_destroy(h);
return 0;
}