CODEWITHSUNDEEP
c++recursionlinked-list
WitchKing17
WitchKing17

Reputation: 184

Printing a List Recursively

I'm trying to print the data in each Node in a Linked List using recursion, but I'm getting out of bounds errors, so I think something's wrong with my recursive function.

Here's the header file:

class List
{
public:
    void print(std::ostream &out) const {}
private:
    Node *head;
    void printList(std::ostream&, const Node*) const;
}

Basically, I'm calling the private helper function from the public print function. Here's the code for the two functions:

void List::print(std::ostream& out) const
{
    printList(out, head);
}

void List::printList(std::ostream& out, const Node* n) const
{
    if(n->next == NULL) {
        out << n->data << std::endl;
        return;
    }

    out << n->data << std::endl;

    printList(out, n->next);
}

I think the problem lies within my if block because I need to stop if there is no next Node, but also print the data in the current Node before returning, but since I already call n->next at the end in printList(out, n->next), do I need to do it in my if block?

Is there a better way to do this recursively? Does the code work for anyone else? I can't seem to get it to work.

Upvotes: 3

Views: 2101

Answers (1)

Shravan40
Shravan40

Reputation: 9908

You need to change the condition inside if(). You should check whether current node is NULL or not instead of next node. 

void List::printList(std::ostream& out, const Node* n) const { 
    if(n == NULL) { 
        return; 
    } 
    out << n->data << std::endl; 
    printList(out, n->next); 
}

Upvotes: 5

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