int main(int argc, char *argv[]) 
{  
    while (1)
    {
        printf("Please input the command:\n");
        printf("1. Insert\n");
        printf("2. Delete\n");
        printf("3. Search\n");
        printf("4. Exit\n");
        printf("Please input the command:\n");
        scanf("%d", &command);
        switch (command)
        {
            case 1:
                printf("Please input the key:\n");
                scanf("%d", &key);
                printf("Please input the value:\n");
                scanf("%d", &value);
                printf("Please input the flag:\n");
                scanf("%d", &flag);
                break;
            default:
                break;
        }

    }
    
}