c++ one way linked list, function doesn't use public class variables

Question

im getting an error on 'head','tail','cur' and etc. was not declared in this scope starting from line 43. Here is the code :

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



using namespace std;
struct studentas
{
    int numeris;
    string vardas;
    char pazymys;
    studentas *next;
};
class list
{
    private:
    studentas *head, *tail;
    public:
    list()
    {
        head=NULL;
        tail=NULL;
    }
};

char random()
{
    static char c = 'A' + rand()%6;
    return c;
}


void kurti(int &n, string v[])
{
    cout << "kiek noresite studentu?" << endl;
    cin >> n;
    for (int i=0; i<n; i++)
    {
        studentas *temp=new studentas;
        temp->numeris=rand()%10;
        temp->vardas=v[rand()%10];
        temp->pazymys=random();
        temp->next=NULL;
        if (head==NULL)
        {
            head=temp;
            tail=temp;
            temp=NULL;
        }
        else
        {
            tail->next=temp;
            tail=temp;
        }
    }
}
void rodyti(string v[])
{
    studentas *temp=new studentas;
    temp=head;
    while (temp!=NULL)
    {
        cout << temp->numeris << endl;
        cout << temp->vardas << endl;
        cout << temp-> pazymys << endl;
        temp=temp->next;
    }
}
void ideti(int pos, int n, string v[])
{
    studentas *pre=new studentas;
    studentas *db=new studentas;
    node *temp=new node;
    db=head;
    for (int i=1;i<pos;i++)
    {
        pre=db;
        db=db->next;
    }
    temp->numeris=rand()%10;
    temp->vardas=v[rand()%10];
    temp->pazymys=random();
    pre->next=temp;
    temp->next=cur;
}
int main()
{
    int n;
    string v[] = {"Adyss","Benas","Vycka","Koste","Petras","Gytis","Audrius","Juste","Ema","Vaidis"};
    kurti(n,v);
    rodyti(v);
    ideti(pos,n,v);
    return 0;

}

I was looking for some post's about using class in functions but tried some of them, still doesn't work..