diff --git a/codes/c/CMakeLists.txt b/codes/c/CMakeLists.txt index 0f4179a0f..8a58eaa92 100644 --- a/codes/c/CMakeLists.txt +++ b/codes/c/CMakeLists.txt @@ -9,8 +9,9 @@ add_subdirectory(include) add_subdirectory(chapter_computational_complexity) add_subdirectory(chapter_array_and_linkedlist) add_subdirectory(chapter_stack_and_queue) +add_subdirectory(chapter_heap) +add_subdirectory(chapter_hashing) add_subdirectory(chapter_binary_search) add_subdirectory(chapter_tree) -add_subdirectory(chapter_heap) add_subdirectory(chapter_searching) -add_subdirectory(chapter_sorting) +add_subdirectory(chapter_sorting) \ No newline at end of file diff --git a/codes/c/chapter_hashing/CMakeLists.txt b/codes/c/chapter_hashing/CMakeLists.txt new file mode 100644 index 000000000..7fa75fd5e --- /dev/null +++ b/codes/c/chapter_hashing/CMakeLists.txt @@ -0,0 +1,2 @@ +add_executable(array_hash_map array_hash_map.c) + diff --git a/codes/c/chapter_hashing/array_hash_map.c b/codes/c/chapter_hashing/array_hash_map.c new file mode 100644 index 000000000..1159fc04a --- /dev/null +++ b/codes/c/chapter_hashing/array_hash_map.c @@ -0,0 +1,215 @@ +/** + * File: array_hash_map.c + * Created Time: 2023-03-18 + * Author: Guanngxu (446678850@qq.com) + */ + +#include "../include/include.h" + +/* 哈希表默认数组大小 */ +# define HASH_MAP_DEFAULT_SIZE 100 + +/* 键值对 int->string */ +struct Entry { + int key; + char *val; +}; + +typedef struct Entry Entry; + +/* 用于表示键值对、键、值的集合 */ +struct MapSet { + void *set; + int len; +}; + +typedef struct MapSet MapSet; + +/* 基于数组简易实现的哈希表 */ +struct ArrayHashMap { + Entry *buckets[HASH_MAP_DEFAULT_SIZE]; +}; + +typedef struct ArrayHashMap ArrayHashMap; + +/* 哈希表初始化函数 */ +ArrayHashMap *newArrayHashMap() { + ArrayHashMap *arrayHashMap = malloc(sizeof(ArrayHashMap)); + return arrayHashMap; +} + +/* 哈希函数 */ +int hashFunc(int key) { + int index = key % HASH_MAP_DEFAULT_SIZE; + return index; +} + +/* 查询操作 */ +const char *get(const ArrayHashMap *d, const int key) { + int index = hashFunc(key); + const Entry *pair = d->buckets[index]; + if (pair == NULL) + return NULL; + return pair->val; +} + +/* 添加操作 */ +void put(ArrayHashMap *d, const int key, const char *val) { + Entry *pair = malloc(sizeof(Entry)); + pair->key = key; + pair->val = malloc(strlen(val) + 1); + strcpy(pair->val, val); + + int index = hashFunc(key); + d->buckets[index] = pair; +} + +/* 删除操作 */ +void removeItem(ArrayHashMap *d, const int key) { + int index = hashFunc(key); + free(d->buckets[index]->val); + free(d->buckets[index]); + d->buckets[index] = NULL; +} + +/* 获取所有键值对 */ +void entrySet(ArrayHashMap *d, MapSet *set) { + Entry *entries; + int i = 0, index = 0; + int total = 0; + + /* 统计有效 entry 数量 */ + for (i = 0; i < HASH_MAP_DEFAULT_SIZE; i++) { + if (d->buckets[i] != NULL) { + total++; + } + } + + entries = malloc(sizeof(Entry) * total); + for (i = 0; i < HASH_MAP_DEFAULT_SIZE; i++) { + if (d->buckets[i] != NULL) { + entries[index].key = d->buckets[i]->key; + entries[index].val = malloc(strlen(d->buckets[i]->val + 1)); + strcpy(entries[index].val, d->buckets[i]->val); + index++; + } + } + + set->set = entries; + set->len = total; +} + +/* 获取所有键 */ +void keySet(ArrayHashMap *d, MapSet *set) { + int *keys; + int i = 0, index = 0; + int total = 0; + + /* 统计有效 entry 数量 */ + for (i = 0; i < HASH_MAP_DEFAULT_SIZE; i++) { + if (d->buckets[i] != NULL) { + total++; + } + } + + keys = malloc(total * sizeof(int)); + for (i = 0; i < HASH_MAP_DEFAULT_SIZE; i++) { + if (d->buckets[i] != NULL) { + keys[index] = d->buckets[i]->key; + index++; + } + } + + set->set = keys; + set->len = total; +} + +/* 获取所有值 */ +void valueSet(ArrayHashMap *d, MapSet *set) { + char **vals; + int i = 0, index = 0; + int total = 0; + + /* 统计有效 entry 数量 */ + for (i = 0; i < HASH_MAP_DEFAULT_SIZE; i++) { + if (d->buckets[i] != NULL) { + total++; + } + } + + vals = malloc(total * sizeof(char *)); + for (i = 0; i < HASH_MAP_DEFAULT_SIZE; i++) { + if (d->buckets[i] != NULL) { + vals[index] = d->buckets[i]->val; + index++; + } + } + + set->set = vals; + set->len = total; +} + +/* 打印哈希表 */ +void print(ArrayHashMap *d) { + int i; + MapSet set; + entrySet(d, &set); + Entry *entries = (Entry*) set.set; + for (i = 0; i < set.len; i++) { + printf("%d -> %s\n", entries[i].key, entries[i].val); + } + free(set.set); +} + +/* Driver Code */ +int main() { + /* 初始化哈希表 */ + ArrayHashMap * map = newArrayHashMap(); + + /* 添加操作 */ + // 在哈希表中添加键值对 (key, value) + put(map, 12836, "小哈"); + put(map, 15937, "小啰"); + put(map, 16750, "小算"); + put(map, 13276, "小法"); + put(map, 10583, "小鸭"); + printf("\n添加完成后,哈希表为\nKey -> Value\n"); + print(map); + + /* 查询操作 */ + // 向哈希表输入键 key ,得到值 value + const char * name = get(map, 15937); + printf("\n输入学号 15937 ,查询到姓名 %s\n", name); + + /* 删除操作 */ + // 在哈希表中删除键值对 (key, value) + removeItem(map, 10583); + printf("\n删除 10583 后,哈希表为\nKey -> Value\n"); + print(map); + + /* 遍历哈希表 */ + int i; + + printf("\n遍历键值对 Key->Value\n"); + print(map); + + MapSet set; + + keySet(map, &set); + int *keys = (int*) set.set; + printf("\n单独遍历键 Key\n"); + for (i = 0; i < set.len; i++) { + printf("%d\n", keys[i]); + } + free(set.set); + + valueSet(map, &set); + char **vals = (char**) set.set; + printf("\n单独遍历键 Value\n"); + for (i = 0; i < set.len; i++) { + printf("%s\n", vals[i]); + } + free(set.set); + + return 0; +}