C语言哈斯图代码

以下是一个简单的C语言哈希表代码示例：

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

#define TABLE_SIZE 1000

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

typedef struct HashTable {
    Node* nodes[TABLE_SIZE];
} HashTable;

int hash(char* key) {
    int hash = 0;
    for (int i = 0; i < strlen(key); ++i) {
        hash = (hash * 31 + key[i]) % TABLE_SIZE;
    }
    return hash;
}

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

void insert(HashTable* table, char* key, int value) {
    int index = hash(key);
    Node* node = table->nodes[index];
    while (node != NULL) {
        if (strcmp(node->key, key) == 0) {
            node->value = value;
            return;
        }
        node = node->next;
    }
    Node* new_node = create_node(key, value);
    new_node->next = table->nodes[index];
    table->nodes[index] = new_node;
}

int lookup(HashTable* table, char* key) {
    int index = hash(key);
    Node* node = table->nodes[index];
    while (node != NULL) {
        if (strcmp(node->key, key) == 0) {
            return node->value;
        }
        node = node->next;
    }
    return -1;
}

int main() {
    HashTable* table = (HashTable*)malloc(sizeof(HashTable));
    insert(table, "apple", 1);
    insert(table, "banana", 2);
    insert(table, "cherry", 3);
    printf("%d\n", lookup(table, "apple"));
    printf("%d\n", lookup(table, "banana"));
    printf("%d\n", lookup(table, "cherry"));
    printf("%d\n", lookup(table, "orange"));
    return 0;
}

在该示例中，哈希表使用链表解决冲突。可以看到，哈希函数通过将键的字符转换为整数，然后使用取模运算将其映射到哈希表的索引。在插入和查找时，将使用哈希函数计算键的哈希值，并使用该值来访问哈希表中的节点。如果发生冲突，则使用链表解决冲突。