// Solution 2: Using recursive
ListNode* reverseList(ListNode* head) {
    if (head == nullptr || head->next == nullptr) return head;

    std::function<ListNode*(ListNode*, ListNode*)> reverseHelper = [&](ListNode *curr, ListNode *prev) -> ListNode*
    {
        if (curr == nullptr) return prev;

        ListNode *next = curr->next;
        curr->next = prev;
        prev = curr;

        return reverseHelper(next, prev);
    };

    return reverseHelper(head, nullptr);
}
Esempio n. 2
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// Performs recursive step of reverse process
Value *reverseHelper(Value *list, Value *newlist) {
    assert(isNull(list) || list->type == CONS_TYPE);
    if (isNull(list)) {
        return newlist;
    } else {
        newlist = cons(copy_Value(car(list)), newlist);
        return reverseHelper(cdr(list), newlist);
    }
}
Esempio n. 3
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// Return a new list that is the reverse of the one that is passed in.
Value *reverse(Value *list){
    Value *newlist = makeNull();
    newlist = reverseHelper(list, newlist);
    return newlist;
}