linux hash 表

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define TABLE_SIZE 10

typedef struct Node {
    char *key;
    int value;
    struct Node *next;
} Node;

Node* create_node(char *key, int value) {
    Node *node = malloc(sizeof(Node));
    node->key = strdup(key);
    node->value = value;
    node->next = NULL;
    return node;
}

void insert(Node **table, char *key, int value) {
    unsigned int hash = 0;
    while (*key) hash = (hash << 5) + *key++;
    Node *node = table[hash % TABLE_SIZE];
    while (node) {
        if (strcmp(node->key, key) == 0) {
            node->value = value;
            return;
        }
        node = node->next;
    }
    node = create_node(key, value);
    node->next = table[hash % TABLE_SIZE];
    table[hash % TABLE_SIZE] = node;
}

int lookup(Node **table, char *key) {
    unsigned int hash = 0;
    while (*key) hash = (hash << 5) + *key++;
    Node *node = table[hash % TABLE_SIZE];
    while (node) {
        if (strcmp(node->key, key) == 0) {
            return node->value;
        }
        node = node->next;
    }
    return -1; // Not found
}

void free_table(Node **table) {
    for (int i = 0; i < TABLE_SIZE; i++) {
        Node *node = table[i];
        while (node) {
            Node *temp = node;
            node = node->next;
            free(temp->key);
            free(temp);
        }
    }
    free(table);
}

int main() {
    Node **table = calloc(TABLE_SIZE, sizeof(Node*));
    insert(table, "test", 1);
    printf("Value for 'test': %d
", lookup(table, "test"));
    free_table(table);
    return 0;
}