Lista ligada utilizando smart find com ponteiro duplo

linked_list_recursive_double_pointer.cpp

#include <iostream>

using namespace std;

struct snode{
    int value;
    snode * next;
    snode(int v = 0, snode * n = nullptr){
        value = v;
        next = n;
    }
};


struct slist{
    snode * head;

    slist(){
        head = new snode(0);
    }

    snode ** _find(snode ** node, int value){
        if(*node == nullptr)
            return node;
        if((*node)->value == value)
           return node;
        return _find(&(*node)->next, value);
    }

    snode ** find(int value){
        return _find(&(head->next), value);
    }

    void remove(int value){
        auto place = find(value);
        if(*place == nullptr)
            return;

        snode * next = (*place)->next;
        delete (*place);
        *place = next;
    }

    snode ** end(snode ** node){
        if(*node == nullptr)
            return node;
        return end(&(*node)->next);
    }

    void push_back(int value){
        auto place = end(&head);
        *place = new snode(value);
    }
};

ostream & operator <<(ostream & os, slist lista){
    auto node = lista.head->next;
    os << "[ ";
    while(node != nullptr){
        os << node->value << " ";
        node = node->next;
    }
    os << "]" << endl;
    return os;
}

int main(){
    slist lista;
    string op = "";
    while(op != "q"){
        cout << "i value - push_back; r value - remove; q quit" << endl;
        cin >> op;
        if(op == "i"){
            int value;
            cin >> value;
            lista.push_back(value);
            cout << lista << endl;
        }
        if(op == "r"){
            int value;
            cin >> value;
            lista.remove(value);
            cout << lista << endl;
        }
    }
    return 0;
}