C++ fibonacci

#include<iostream>
using namespace std;
int *arr;
int iter = 0;
int len;
int returnValue;
void exist(int num, int arr[] )
{
    bool checkExistance = false;
    returnValue = num;
    for (int i = 0; i< len; i++)
    {
        if(arr[i]==num)
        {
            checkExistance = true;
            break;
        }
    }
    if(!checkExistance)
    {
        arr[iter]=num;
        iter++;
    }
}
int fibonacci(int n)
{   
    if (n==1)
    {
        exist(1,arr);
        return 1;
    }   
    else if (n==2)
    {
        exist(1,arr);
        return 1;
    }
    else
    {
        exist((fibonacci(n-1)+fibonacci(n-2)),arr);
        return returnValue;
    }
}
int main()
{
    int n;
    cout<<"Vpisi stevilko: ";
    cin>>n;
    len = n;
    arr = new int[n];
    fibonacci(n);
    arr[n-1] = 1;
    cout<<"1:\t"<<arr[n-1]<<endl;
    for (int i = 0; i< len-1; i++)
    {
        cout<<i+2<<":\t"<<arr[i]<<endl;
    }
    return 0;
}