c语言哈希表电话号码查询系统源代码

以下是一个简单的基于哈希表实现的电话号码查询系统的C语言源代码：

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

#define TABLE_SIZE 100

typedef struct node {
    char name[20];
    char phone[20];
    struct node *next;
} Node;

Node *table[TABLE_SIZE];

unsigned int hash(char *str) {
    unsigned int hash = 5381;
    int c;

    while ((c = *str++))
        hash = ((hash << 5) + hash) + c;

    return hash % TABLE_SIZE;
}

Node *find(char *name) {
    unsigned int index = hash(name);
    Node *p;

    for (p = table[index]; p != NULL; p = p->next)
        if (strcmp(name, p->name) == 0)
            return p;

    return NULL;
}

void insert(char *name, char *phone) {
    unsigned int index = hash(name);
    Node *p;

    for (p = table[index]; p != NULL; p = p->next)
        if (strcmp(name, p->name) == 0) {
            strcpy(p->phone, phone);
            return;
        }

    p = (Node *) malloc(sizeof(Node));
    strcpy(p->name, name);
    strcpy(p->phone, phone);
    p->next = table[index];
    table[index] = p;
}

void delete(char *name) {
    unsigned int index = hash(name);
    Node *p, *q;

    for (q = NULL, p = table[index]; p != NULL; q = p, p = p->next)
        if (strcmp(name, p->name) == 0) {
            if (q == NULL)
                table[index] = p->next;
            else
                q->next = p->next;

            free(p);
            return;
        }
}

void display() {
    int i;
    Node *p;

    for (i = 0; i < TABLE_SIZE; ++i)
        for (p = table[i]; p != NULL; p = p->next)
            printf("%s\t%s\n", p->name, p->phone);
}

int main() {
    char name[20], phone[20];
    int choice;

    while (1) {
        printf("\nTelephone directory\n");
        printf("1. Find\n2. Insert\n3. Delete\n4. Display\n5. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter name: ");
                scanf("%s", name);

                Node *p = find(name);

                if (p)
                    printf("%s\t%s\n", p->name, p->phone);
                else
                    printf("Name not found\n");

                break;

            case 2:
                printf("Enter name: ");
                scanf("%s", name);
                printf("Enter phone number: ");
                scanf("%s", phone);

                insert(name, phone);

                break;

            case 3:
                printf("Enter name: ");
                scanf("%s", name);

                delete(name);

                break;

            case 4:
                display();

                break;

            case 5:
                exit(0);

            default:
                printf("Invalid choice\n");
        }
    }

    return 0;
}

该程序使用了一个大小为100的哈希表来存储电话号码。它实现了四个基本操作：查找、插入、删除和显示。在运行程序时，用户可以选择要执行的操作。如果选择插入操作，则需要输入姓名和电话号码。如果选择查找操作，则需要输入姓名，程序将输出该姓名对应的电话号码。如果选择删除操作，则需要输入姓名，程序将从哈希表中删除该用户的信息。如果选择显示操作，则程序将输出哈希表中所有用户的姓名和电话号码。