Size of linked lists without traversing list

[mallikar]

Hi every body,

I have a linear single list , so, how to find out the length of the linked list w/o traversing the linked list.....


Thanks in Advance

[sicarie]

Keep an int i_linkedListSize variable that has the size, and modify it as you add/remove nodes.

This is rather poor form, though. If you forget to modify this anywhere you modify your list in your code (or if someone else comes and tries to use your code later), and they forget, you run into problems.

[weaknessforcats]

You can minimize the danger by using a struct for the list:

struck LinkedList
{
    int numNodes;
    Node* start;          //start of the list
    Node* end;           //end of the list;
    Node* current;      //our current position in the list.
};
 

and a separate struct for the Node.

Then carefully ensure your functions update the LinkedList consistently.

This type of design a called a cursor-based list.

[kornkid4032]

Is this the ONLY way to know the size of the list without traversing it?