如何使用哈希表保存用户登录/注册的数据？

如何解决如何使用哈希表保存用户登录/注册的数据？

我正在尝试使用客户端和服务器为 C 语言的游戏制作登录/注册功能。用户应该能够注册、登录，哈希表将能够知道使用了什么用户名或密码是否不正确。我认为我的代码有效，但是当程序结束时，哈希表再次重置，这使得它毫无意义。有没有办法保存用户名和密码，这样它就不会使用我已经制作的代码重置？

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

// hash function
int hashFunction(const char* username){
    int result = 0;
    for(int i = 0; i < strlen(username); i++){
        result = (13*result + username[i]) % 3119;
    }
    return result;
}

void login_register(int mode,char* username,char* password,char hashTable[][21]){
    if(mode == 1) { // register mode will be 1
        char new_username[21];
        while(1){
            printf("Enter a username.\n");
            scanf("%s",new_username);
            // check for duplicate here
            int hashResult = hashFunction(new_username);
            if(strcmp(hashTable[hashResult%128],".") == 0){
                strcpy(username,new_username);
                break;
            }
            else {
                printf("Username is taken try again.\n");
            }
        }
        char new_password[21];
        printf("Enter a password.\n");
        scanf("%s",new_password);
        // copy over the newly input values into the parameters
        strcpy(password,new_password);
    }
    
    else{
        char new_username[21];
        char new_password[21];
        printf("Enter your username.\n");
        scanf("%s",new_username);
        strcpy(username,new_username);
        
        while(1){
            printf("Enter your password.\n");
            scanf("%s",new_password);
            strcpy(password,new_password);
            // check for duplicate here
            int hashResult = hashFunction(new_username);
            if(strcmp(hashTable[hashResult%128],password ) == 0){
                break;
            }
            else {
                printf("Password is incorrect try again.\n");
            }
        }
        
    }
        
}



int main()
{
    char hashTable[128][21];
    // 128 total strings in the array
    //each string will be 20 chars long plus the '\0' at the end of each string
    for(int i = 0; i < 128; i++){
        strcpy(hashTable[i],"."); // we initialize each index of the hash table to just have a default value so we have something to compare against
    }
    int mode = 1;
    char username[21]; // variable to hold the username
    char password[21]; // variable to hold the password
    //strcpy(hashTable[35],"password"); // this was just me testing ignore that
    login_register(mode,username,password,hashTable);
    printf("%s\n",username);
    printf("%s\n",password);
    
}