Thread: printing another field of nodes in a linked list without going over the list again

Say i want to go over a linked list and just count the nodes that satisfy a particular condition. Later i would print value of some field in those nodes. I could go over the list again but the bigger the list the more time it would take.
I think i read before that one option is to store the pointers of the nodes of interest in an array of pointers. Is that a good solution? Are there better solutions?
I imagine there will always be comprimise between time and space. Would like to know what is the best solution for this problem.

Originally Posted by telmo_d

I think i read before that one option is to store the pointers of the nodes of interest in an array of pointers. Is that a good solution?

Yes.

Originally Posted by telmo_d

Are there better solutions?

Perhaps you could print them even as you count them (i.e., if you do not need to display the count before printing the first matching node). The bad part is that this tightly couples the counting and the printing.

The problem is that you used sizeof(Node) instead of sizeof(Node*). To avoid such problems, get into the habit of making use of the array name in the sizeof expression, e.g.,

Code:

Node** array = calloc(100, sizeof(array[0]));

You should also check that calloc did not return a null pointer before assigning to array[0].