вот эти списки работают точно

#include <iostream>
#include <string>
#include <fstream>
using namespace std;

ifstream in("input.txt");
ofstream out("output.txt");

class list
{
    struct element
    {
        string inf;
        element* next;
        element(string x) :inf(x), next(0) {}
    };
    int count = 0;
    element* head;
    int size;
    element* findx(string x)
    {
        element* cur = head;
        for (int i = 1; i < size; i++)
        {
            if (cur->inf == x)
            {
                return cur;
            }
            cur = cur->next;
        }
    }
    element* find(int index)
    {
        if ((index < 0) || (index > size))
        {
            return nullptr;
        }
        else
        {
            element* cur = head;
            for (int i = 1; i < index; i++)
            {
                cur = cur->next;
            }
            return cur;
        }
    }
public:
    list() :head(0), size(0) {}
    bool empty()
    {
        return head == 0;
    }
    int getlength()
    {
        return size;
    }
    string getx(string x)
    {
        element* r = findx(x);
        string i = r->inf;
        return i;
    }
    string get(int index)
    {
        element* r = find(index);
        string i = r->inf;
        return i;
    }
    void insert(int index, string data)
    {
        element* newptr = new element(data);
        size = getlength() + 1;
        if (index == 1)
        {
            newptr->next = head;
            head = newptr;
        }
        else
        {
            element* prev = find(index - 1);
            newptr->next = prev->next;
            prev->next = newptr;
        }
    }
    void remove(int index)
    {
        element* cur;
        --size;
        if (index == 1)
        {
            cur = head;
            head = head->next;
        }
        else
        {
            element* prev = find(index - 1);
            cur = prev->next;
            prev->next = cur->next;
        }
        cur->next = nullptr;
        delete cur;
    }
    void print()
    {
        for (element* cur = head; cur != nullptr; cur = cur->next)
        {
            out << cur->inf << ' ';
        }
        out << endl;
    }
};

int main()
{
    list ls, kk;
    string value;
    while (in >> value)
    {
        ls.insert(ls.getlength() + 1, value);
    }
    in.close();
    int ind = 1;
    while (!ls.empty()) {
        string i = ls.get(0);
        kk.insert(ind, i);
        ind++;
        if (i.length() == 1) {
            kk.insert(ind, i);
            ind++;
        }
        ls.remove(1);
    }

    kk.print();
    return 0;
}

aarrarar
r
t
base
baza
h
pp