uthash
一个实现 Hash 的库
- doc：https://troydhanson.github.io/uthash/
- project：https://github.com/troydhanson/uthash
- 特点
- 用宏的方式实现，支持任意数据结构作为 key（包括 struct）
使用方法：
- 把 src/uthash.h 复制到本地
#include "uthash.h"
基本操作
- 增 add
- 删 delete
- 改 replace
- 查 find
- 迭代器 iterate
- 排序 sort
使用
我写的：（排序就先不写了）
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "uthash.h"
struct hashTable {
int key;
int val;
UT_hash_handle hh;
};
struct hashTable *hashtable;
//查
struct hashTable *find(int ikey) {
struct hashTable *tmp;
HASH_FIND_INT(hashtable, &ikey, tmp);
return tmp;
}
//插入、替换
void insert(int ikey, int ival) {
struct hashTable *it = find(ikey);
if (it == NULL) {
struct hashTable *tmp = malloc(sizeof(struct hashTable));
tmp->key = ikey, tmp->val = ival;
HASH_ADD_INT(hashtable, key, tmp);
} else {
it->val = ival;
}
}
//删除
void delete(int ikey) {
struct hashTable *it = find(ikey);
if (it != NULL) {
HASH_DEL(hashtable, it);
free(it); // ???有必要吗？
}
};
//清空
void delete_all() {
struct hashTable *current, *tmp;
HASH_ITER(hh, hashtable, current, tmp) {
HASH_DEL(hashtable, current);
free(current);
}
};
void print_hash() {
struct hashTable *it;
for (it = hashtable; it != NULL; it = (struct hashTable *) (it->hh.next)) {
printf("key = %d, val = %d\n", it->key, it->val);
}
};
int main() {
hashtable = NULL; // 千万不能少，不然多次调用会有问题
insert(1, 2);
insert(2, 8);
insert(3, 9);
print_hash();
printf("==========\n");
insert(3, 3);
print_hash();
delete(2);
printf("==========\n");
print_hash();
delete_all();
printf("==========\n");
print_hash();
}
也可以很简单的把key和val改成 char[]（字符串）
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "uthash.h"
struct hashTable {
char key[10];
char val[10];
UT_hash_handle hh;
};
struct hashTable *hashtable;
//查
struct hashTable *find(char *ikey) {
struct hashTable *tmp;
HASH_FIND_STR(hashtable, ikey, tmp);
return tmp;
}
//插入、替换
void insert(char *ikey, char *ival) {
struct hashTable *it = find(ikey);
if (it == NULL) {
struct hashTable *tmp = malloc(sizeof(struct hashTable));
strcpy(tmp->key, ikey);
strcpy(tmp->val, ival);
HASH_ADD_STR(hashtable, key, tmp);
} else {
strcpy(it->val, ival);
}
}
//删除
void delete(char *ikey) {
struct hashTable *it = find(ikey);
if (it != NULL) {
HASH_DEL(hashtable, it);
free(it); // ???有必要吗？
}
};
//清空
void delete_all() {
struct hashTable *current, *tmp;
HASH_ITER(hh, hashtable, current, tmp) {
HASH_DEL(hashtable, current);
free(current);
}
};
void print_hash() {
struct hashTable *it;
for (it = hashtable; it != NULL; it = (struct hashTable *) (it->hh.next)) {
printf("key = %s, val = %s\n", it->key, it->val);
}
};
int main() {
hashtable = NULL; // 千万不能少，不然多次调用会有问题
insert("a", "2");
insert("b", "8");
insert("c", "9");
print_hash();
printf("==========\n");
insert("c", "3");
print_hash();
delete("b");
printf("==========\n");
print_hash();
struct hashTable *res = find("a");
if (res != NULL) {
printf("%s,%s", res->key, res->val);
}
delete_all();
printf("==========\n");
print_hash();
}
参考：https://blog.csdn.net/a123441/article/details/89045293
