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147 lines
3.7 KiB
C
147 lines
3.7 KiB
C
/**
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* File: hashing_search.c
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* Created Time: 2023-04-15
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* Author: Gonglja (glj0@outlook.com)
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*/
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#include "../utils/common.h"
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/* 哈希表 */
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struct hashTable {
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int key;
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void *val;
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UT_hash_handle hh; // 基于 uthash.h 实现
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};
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typedef struct hashTable hashTable;
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/* 打印哈希表（当 hashTable 中 val 为 int 型使用这个） */
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void printHashTableVal(hashTable **ht) {
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struct hashTable *s;
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for (s = *ht; s != NULL; s = s->hh.next) {
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printf("key: %d: val: %d\n", s->key, *(int *)(s->val));
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}
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}
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/* 打印哈希表（当 hashTable 中 val 为 ListNode* 型使用这个） */
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void printHashTableLinklist(hashTable **ht) {
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struct hashTable *s;
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for (s = *ht; s != NULL; s = s->hh.next) {
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printf("key: %d: val: %d\n", s->key, ((ListNode *)s->val)->val);
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}
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}
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/* 哈希表查找 */
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hashTable *find(hashTable *ht, int k) {
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hashTable *s;
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HASH_FIND_INT(ht, &k, s);
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return s;
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}
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/* 添加 k、v 到哈希表 ht 中，v 为 int 类型 */
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void addInt(hashTable **ht, int k, int v) {
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hashTable *s;
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HASH_FIND_INT(*ht, &k, s);
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if (s == NULL) {
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s = malloc(sizeof(*s));
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s->key = k;
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HASH_ADD_INT(*ht, key, s);
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}
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int *tmp = malloc(sizeof(*s->val));
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*tmp = v;
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s->val = tmp;
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}
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/* 添加 k、v 到哈希表 ht 中，v 为 ListNode* 类型 */
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void addLinkNode(hashTable **ht, int k, ListNode *v) {
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hashTable *s;
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HASH_FIND_INT(*ht, &k, s);
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if (s == NULL) {
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s = malloc(sizeof(*s));
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s->key = k;
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HASH_ADD_INT(*ht, key, s);
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}
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s->val = (void *)v;
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}
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/* 删除 ht 中所有元素 */
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void deleteAll(hashTable **ht) {
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hashTable *curr, *tmp;
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HASH_ITER(hh, *ht, curr, tmp) {
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HASH_DEL(*ht, curr);
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free(curr);
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}
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}
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/* 通过 key 访问哈希表，返回 int 类型 */
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int accessInt(hashTable **h, int key) {
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hashTable *s;
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int ret = -1;
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if (s = find(*h, key)) {
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ret = *(int *)s->val;
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}
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return ret;
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}
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/* 通过 key 访问哈希表，返回 ListNode* 类型 */
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ListNode *accessLinkNode(hashTable **h, int key) {
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hashTable *s;
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ListNode *res = NULL;
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if (s = find(*h, key)) {
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res = (ListNode *)s->val;
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}
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return res;
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}
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/* 哈希查找（数组） */
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int hashingSearchArray(hashTable **ht, int target) {
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// 哈希表的 key: 目标元素，value: 索引
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// 若哈希表中无此 key ，返回 -1
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if (find(*ht, target) == NULL)
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return -1;
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return accessInt(ht, target);
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}
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/* 哈希查找（链表） */
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ListNode *hashingSearchLinkedList(hashTable **ht, int target) {
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// 哈希表的 key: 目标节点值，value: 节点对象
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// 若哈希表中无此 key ，返回 nullptr
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if (find(*ht, target) == NULL)
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return NULL;
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return accessLinkNode(ht, target);
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}
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/* Driver Code */
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int main() {
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int target = 3;
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/* 哈希查找（数组） */
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int nums[] = {1, 5, 3, 2, 4, 7, 5, 9, 10, 8};
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// 初始化哈希表
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hashTable **ht = malloc(sizeof(*ht));
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*ht = NULL;
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for (int i = 0; i < sizeof(nums) / sizeof(nums[0]); i++) {
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addInt(ht, nums[i], i); // key: 元素，value: 索引
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}
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int index = hashingSearchArray(ht, target);
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printf("目标元素 3 的索引 = %d\r\n", index);
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deleteAll(ht);
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/* 哈希查找（链表） */
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ListNode *head = arrToLinkedList(nums, sizeof(nums) / sizeof(nums[0]));
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// 初始化哈希表
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hashTable **ht1 = malloc(sizeof(*ht));
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*ht1 = NULL;
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while (head != NULL) {
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addLinkNode(ht1, head->val, head); // key: 节点值，value: 节点
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head = head->next;
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}
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ListNode *node = hashingSearchLinkedList(ht1, target);
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if (node)
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printf("目标节点值 3 的对应节点对象为 %#p val: %d\r\n", node, node->val);
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deleteAll(ht1);
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return 0;
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}
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